Merge branch 'main' into dev-4.7.0

Konflikte in den Steuer-Dateien zugunsten der weiterentwickelten lokalen Version
aufgelöst: vat_pricing_mode (Preismodus), DB-gestützte tax_exemption_reasons mit FK,
typisierte Request-DTOs, Event-Steuer-Snapshot. origin/dev-4.7.0 enthielt eine
frühere Teilmenge desselben Features.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

.env.example

@@ -56,6 +56,8 @@ MAIL_PASSWORD=null
 MAIL_FROM_ADDRESS="hello@example.com"
 MAIL_FROM_NAME="${APP_NAME}"
 
+APP_ADMIN_MAIL=
+
 AWS_ACCESS_KEY_ID=
 AWS_SECRET_ACCESS_KEY=
 AWS_DEFAULT_REGION=us-east-1

CLAUDE.md

@@ -15,3 +15,60 @@ Routing, Mails) stehen in `.ai/conventions.md` und werden hier eingebunden — *
 
 - [Zahlungsmodule](app/EventPaymentModules/CLAUDE.md) — interface-gesteuerte Zahlungsarten (Optionen, Config,
   Anmelde-Zusammenfassung, GiroCode/Fähigkeits-Interfaces, neues Modul hinzufügen).
+
+## Umsatzsteuer / Steuerinformationen
+
+Rechtlich korrekter Begriff ist **Umsatzsteuer (USt)**, nicht MwSt. Ziel: tagesbasierte Anmelde-Rechnungen („Teilnahme
+Veranstaltung X in Gruppe Y" × Anwesenheitstage × Beitrag/Tag). Grundlage ist gebaut, die Rechnungs-PDF/-berechnung
+folgt noch.
+
+### Tenant-Einstellungen (Tab „Steuerinformationen")
+
+Felder auf `tenants` (Self-Service `TenantData.vue` + verwaltet `TenantEdit.vue`, Partial `TenantTaxInfo.vue`,
+Controller `TenantTax*` / `ManagedTenantTax*`, Action `UpdateTenantTax`):
+
+- `tax_liable` (bool) — ob USt-Pflicht besteht.
+- `vat_rate` (int, %) — USt-Satz, nur relevant wenn `tax_liable` (0–100, geclamped).
+- `vat_pricing_mode` (Enum `App\Enumerations\VatPricingMode`, natives PHP-Enum: `inclusive` | `add_on`).
+- `tax_exemption_reason` (FK → `tax_exemption_reasons.slug`, nullable) — Grund wenn **nicht** steuerpflichtig.
+  DB-Default neuer Tenants: `ustg_4_25a` (Jugendhilfe).
+- `tax_exemption_note` (text, nullable) — Freitext, nur bei Grund `custom` (`requires_note`).
+
+### Preismodus — **das Kernverhalten**
+
+Es wird **immer der finale Brutto-Beitrag** pro Anmeldung gespeichert (`EventParticipant.amount`, keine USt-Spalten am
+Teilnehmer). Der Modus wirkt **nur bei der Preisermittlung im Anmeldeprozess**:
+
+- **`inclusive`** (Brutto / „zusammenfassen", Supermarkt-Prinzip, Default): der konfigurierte Beitrag **ist** der
+  Endpreis, USt ist bereits enthalten → Preis bleibt gleich; die USt wird erst **auf der Rechnung herausgerechnet**:
+  `USt = brutto × Satz / (100 + Satz)`, `netto = brutto − USt`.
+- **`add_on`** (Netto / „aufaddieren"): der konfigurierte Beitrag ist netto → Endpreis = `Beitrag × (1 + Satz/100)`. Die
+  USt wird bei der Anmeldung **aufgeschlagen** → Teilnehmer zahlt mehr.
+
+Umsetzung in `App\Resources\EventResource::calculateAmount()`: nach allen Multiplikatoren (Early-Bird, `pay_per_day`,
+Geschwister) gilt
+`if ($event->tax_liable && $event->vat_pricing_mode === VatPricingMode::AddOn->value) $fee->multiply(1 + $event->vat_rate/100);`
+danach `round(…, 2)`. Bei `inclusive`/nicht steuerpflichtig bleibt der Beitrag unverändert.
+
+### Event-Snapshot (unveränderlich)
+
+Bei Event-Anlage (`CreateEventCommand::execute()`) werden `tax_liable`, `vat_rate`, `vat_pricing_mode`,
+`tax_exemption_reason`, `tax_exemption_note` aus dem Tenant **auf das Event kopiert und dort eingefroren** (Spalten auf
+`events`). Preisermittlung und spätere Rechnungen lesen vom Event, nicht vom Tenant → spätere Tenant-Änderungen berühren
+bestehende Events/Rechnungen nicht.
+
+### Befreiungsgründe (DB-gestützt)
+
+Tabelle `tax_exemption_reasons`, Model `App\Enumerations\TaxExemptionReason` (Eloquent, `slug` PK; `name`,
+`invoice_text`, `requires_note`, `sort_order`). `options()` liefert `{value,label,text}` sortiert nach `sort_order`. FK
+von `tenants` **und** `events`. Seed in Migration `170010`, verfeinert in `170020`. Gründe (in Reihenfolge):
+`ustg_19` (§ 19 Kleinunternehmer), `ustg_4_24` (§ 4 Nr. 24 Jugendherbergen),
+`ustg_4_25a` (§ 4 Nr. 25 Buchst. a — Jugendhilfe-Veranstaltungen, Default), `ustg_4_22a` (§ 4 Nr. 22 Buchst. a —
+Vorträge/Kurse), `custom` (Freitext). Jeder Grund kapselt den Rechnungs-Pflichthinweis nach **§ 14 Abs. 4 Nr. 8 UStG**
+(`invoice_text`; bei `custom` der Tenant-Freitext via `invoiceText(?note)`). Gemeinnützigkeit allein befreit **nicht** —
+es braucht immer einen konkreten Rechtsgrund.
+
+### Noch offen (nächster Schritt)
+
+Die eigentliche **Rechnung**: tagesbasierte Positionen, USt aus dem gespeicherten Brutto herausrechnen (Satz vom
+Event-Snapshot); bei Befreiung kein USt-Ausweis, stattdessen der Pflichthinweis des Grundes.

app/Domains/Admin/Actions/UpdateTenantTax/UpdateTenantTaxAction.php

@@ -0,0 +1,66 @@
+<?php
+
+namespace App\Domains\Admin\Actions\UpdateTenantTax;
+
+use App\Enumerations\VatPricingMode;
+
+class UpdateTenantTaxAction
+{
+    public function __construct(private UpdateTenantTaxRequest $request)
+    {
+    }
+
+    public function execute(): UpdateTenantTaxResponse
+    {
+        $response = new UpdateTenantTaxResponse();
+
+        if ($this->request->taxLiable) {
+            $this->request->tenant->update([
+                'tax_liable' => true,
+                'vat_rate' => $this->clampVatRate($this->request->vatRate),
+                'vat_pricing_mode' => $this->request->vatPricingMode->value,
+                'tax_exemption_reason' => null,
+                'tax_exemption_note' => null,
+            ]);
+
+            $response->success = true;
+            $response->message = 'Steuerinformationen wurden gespeichert.';
+
+            return $response;
+        }
+
+        $reason = $this->request->exemptionReason;
+
+        if ($reason === null) {
+            $response->message = 'Bitte einen gültigen Befreiungsgrund auswählen.';
+
+            return $response;
+        }
+
+        $note = trim((string)$this->request->exemptionNote);
+
+        if ($reason->requires_note && $note === '') {
+            $response->message = 'Bitte einen Text für den Befreiungsgrund angeben.';
+
+            return $response;
+        }
+
+        $this->request->tenant->update([
+            'tax_liable' => false,
+            'vat_rate' => 0,
+            'vat_pricing_mode' => VatPricingMode::Inclusive->value,
+            'tax_exemption_reason' => $reason->slug,
+            'tax_exemption_note' => $reason->requires_note ? $note : null,
+        ]);
+
+        $response->success = true;
+        $response->message = 'Steuerinformationen wurden gespeichert.';
+
+        return $response;
+    }
+
+    private function clampVatRate(int $vatRate): int
+    {
+        return max(0, min(100, $vatRate));
+    }
+}

app/Domains/Admin/Actions/UpdateTenantTax/UpdateTenantTaxRequest.php

@@ -0,0 +1,21 @@
+<?php
+
+namespace App\Domains\Admin\Actions\UpdateTenantTax;
+
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Models\Tenant;
+
+class UpdateTenantTaxRequest
+{
+    public function __construct(
+        public Tenant $tenant,
+        public bool $taxLiable,
+        public int $vatRate,
+        public ?TaxExemptionReason $exemptionReason,
+        public ?string $exemptionNote,
+        public VatPricingMode $vatPricingMode,
+    )
+    {
+    }
+}

app/Domains/Admin/Actions/UpdateTenantTax/UpdateTenantTaxResponse.php

@@ -0,0 +1,9 @@
+<?php
+
+namespace App\Domains\Admin\Actions\UpdateTenantTax;
+
+class UpdateTenantTaxResponse
+{
+    public bool $success = false;
+    public string $message = '';
+}

app/Domains/Admin/Controllers/ManagedTenantTaxGetController.php

@@ -0,0 +1,28 @@
+<?php
+
+namespace App\Domains\Admin\Controllers;
+
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Scopes\CommonController;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class ManagedTenantTaxGetController extends CommonController
+{
+    public function __invoke(string $slug, Request $request): JsonResponse
+    {
+        $tenant = $this->adminTenants->findBySlug($slug);
+
+        return response()->json([
+            'tax_liable' => $tenant->tax_liable,
+            'vat_rate' => $tenant->vat_rate,
+            'tax_exemption_reason' => $tenant->tax_exemption_reason,
+            'tax_exemption_note' => $tenant->tax_exemption_note,
+            'vat_pricing_mode' => $tenant->vat_pricing_mode,
+            'exemption_reasons' => TaxExemptionReason::options(),
+            'pricing_modes' => VatPricingMode::options(),
+            'saveEndpoint' => '/api/v1/admin/tenants/' . $slug . '/tax',
+        ]);
+    }
+}

app/Domains/Admin/Controllers/ManagedTenantTaxUpdateController.php

@@ -0,0 +1,35 @@
+<?php
+
+namespace App\Domains\Admin\Controllers;
+
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxAction;
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxRequest;
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Scopes\CommonController;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class ManagedTenantTaxUpdateController extends CommonController
+{
+    public function __invoke(string $slug, Request $request): JsonResponse
+    {
+        $tenant = $this->adminTenants->findBySlug($slug);
+
+        $action = new UpdateTenantTaxAction(new UpdateTenantTaxRequest(
+            tenant: $tenant,
+            taxLiable: $request->boolean('tax_liable'),
+            vatRate: (int)$request->input('vat_rate', 0),
+            exemptionReason: TaxExemptionReason::where('slug', $request->input('tax_exemption_reason'))->first(),
+            exemptionNote: $request->input('tax_exemption_note'),
+            vatPricingMode: VatPricingMode::tryFrom((string) $request->input('vat_pricing_mode', 'inclusive')) ?? VatPricingMode::Inclusive,
+        ));
+
+        $response = $action->execute();
+
+        return response()->json([
+            'status' => $response->success ? 'success' : 'error',
+            'message' => $response->message,
+        ]);
+    }
+}

app/Domains/Admin/Controllers/TenantTaxGetController.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Domains\Admin\Controllers;
+
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Scopes\CommonController;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class TenantTaxGetController extends CommonController
+{
+    public function __invoke(Request $request): JsonResponse
+    {
+        return response()->json([
+            'tax_liable' => $this->tenant->tax_liable,
+            'vat_rate' => $this->tenant->vat_rate,
+            'tax_exemption_reason' => $this->tenant->tax_exemption_reason,
+            'tax_exemption_note' => $this->tenant->tax_exemption_note,
+            'vat_pricing_mode' => $this->tenant->vat_pricing_mode,
+            'exemption_reasons' => TaxExemptionReason::options(),
+            'pricing_modes' => VatPricingMode::options(),
+            'saveEndpoint' => '/api/v1/admin/tenant/tax',
+        ]);
+    }
+}

app/Domains/Admin/Controllers/TenantTaxUpdateController.php

@@ -0,0 +1,33 @@
+<?php
+
+namespace App\Domains\Admin\Controllers;
+
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxAction;
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxRequest;
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Scopes\CommonController;
+use Illuminate\Http\JsonResponse;
+use Illuminate\Http\Request;
+
+class TenantTaxUpdateController extends CommonController
+{
+    public function __invoke(Request $request): JsonResponse
+    {
+        $action = new UpdateTenantTaxAction(new UpdateTenantTaxRequest(
+            tenant: $this->tenant,
+            taxLiable: $request->boolean('tax_liable'),
+            vatRate: (int)$request->input('vat_rate', 0),
+            exemptionReason: TaxExemptionReason::where('slug', $request->input('tax_exemption_reason'))->first(),
+            exemptionNote: $request->input('tax_exemption_note'),
+            vatPricingMode: VatPricingMode::tryFrom((string) $request->input('vat_pricing_mode', 'inclusive')) ?? VatPricingMode::Inclusive,
+        ));
+
+        $response = $action->execute();
+
+        return response()->json([
+            'status' => $response->success ? 'success' : 'error',
+            'message' => $response->message,
+        ]);
+    }
+}

app/Domains/Admin/Routes/api.php

@@ -1,10 +1,5 @@
 <?php
 
-use App\Domains\Admin\Controllers\UserDetailGetController;
-use App\Domains\Admin\Controllers\UserListApiController;
-use App\Domains\Admin\Controllers\UserResetPasswordController;
-use App\Domains\Admin\Controllers\UserToggleActiveController;
-use App\Domains\Admin\Controllers\UserUpdateController;
 use App\Domains\Admin\Controllers\ManagedTenantContactGetController;
 use App\Domains\Admin\Controllers\ManagedTenantContactUpdateController;
 use App\Domains\Admin\Controllers\ManagedTenantGdprGetController;
@@ -13,6 +8,8 @@ use App\Domains\Admin\Controllers\ManagedTenantImpressGetController;
 use App\Domains\Admin\Controllers\ManagedTenantImpressUpdateController;
 use App\Domains\Admin\Controllers\ManagedTenantPaymentGetController;
 use App\Domains\Admin\Controllers\ManagedTenantPaymentUpdateController;
+use App\Domains\Admin\Controllers\ManagedTenantTaxGetController;
+use App\Domains\Admin\Controllers\ManagedTenantTaxUpdateController;
 use App\Domains\Admin\Controllers\TenantContactGetController;
 use App\Domains\Admin\Controllers\TenantContactUpdateController;
 use App\Domains\Admin\Controllers\TenantCreateController;
@@ -24,9 +21,16 @@ use App\Domains\Admin\Controllers\TenantImpressGetController;
 use App\Domains\Admin\Controllers\TenantImpressUpdateController;
 use App\Domains\Admin\Controllers\TenantListApiController;
 use App\Domains\Admin\Controllers\TenantPaymentGetController;
-use App\Domains\Admin\Controllers\TenantPaymentUpdateController;
 use App\Domains\Admin\Controllers\TenantPaymentMethodsGetController;
 use App\Domains\Admin\Controllers\TenantPaymentMethodsUpdateController;
+use App\Domains\Admin\Controllers\TenantPaymentUpdateController;
+use App\Domains\Admin\Controllers\TenantTaxGetController;
+use App\Domains\Admin\Controllers\TenantTaxUpdateController;
+use App\Domains\Admin\Controllers\UserDetailGetController;
+use App\Domains\Admin\Controllers\UserListApiController;
+use App\Domains\Admin\Controllers\UserResetPasswordController;
+use App\Domains\Admin\Controllers\UserToggleActiveController;
+use App\Domains\Admin\Controllers\UserUpdateController;
 use App\Middleware\AdminRoleMiddleware;
 use App\Middleware\IdentifyTenant;
 use App\Middleware\LvOnlyMiddleware;
@@ -44,6 +48,8 @@ Route::middleware([IdentifyTenant::class, 'auth', AdminRoleMiddleware::class])->
         Route::post('/impress', TenantImpressUpdateController::class);
         Route::get('/gdpr', TenantGdprGetController::class);
         Route::post('/gdpr', TenantGdprUpdateController::class);
+        Route::get('/tax', TenantTaxGetController::class);
+        Route::post('/tax', TenantTaxUpdateController::class);
     });
 
     Route::prefix('api/v1/admin/users')->group(function () {
@@ -69,6 +75,8 @@ Route::middleware([IdentifyTenant::class, 'auth', AdminRoleMiddleware::class])->
                 Route::post('/impress', ManagedTenantImpressUpdateController::class);
                 Route::get('/gdpr', ManagedTenantGdprGetController::class);
                 Route::post('/gdpr', ManagedTenantGdprUpdateController::class);
+                Route::get('/tax', ManagedTenantTaxGetController::class);
+                Route::post('/tax', ManagedTenantTaxUpdateController::class);
             });
         });
     });

app/Domains/Admin/Views/Partials/TenantTaxInfo.vue

@@ -0,0 +1,240 @@
+<script setup>
+import {computed, ref} from 'vue';
+import {useAjax} from "../../../../../resources/js/components/ajaxHandler.js";
+import RichSelectBox from "../../../../Views/Components/RichSelectBox.vue";
+import {toast} from "vue3-toastify";
+
+const props = defineProps({
+    data: {
+        type: Object,
+        default: () => ({})
+    },
+})
+
+const {request} = useAjax()
+
+const editing = ref(false)
+
+const reasons = computed(() => props.data.exemption_reasons ?? [])
+const pricingModes = computed(() => props.data.pricing_modes ?? [])
+
+const liableOptions = [
+    {value: '1', label: 'Ja – Umsatzsteuer wird erhoben'},
+    {value: '0', label: 'Nein – umsatzsteuerbefreit'},
+]
+
+const form = ref({
+    tax_liable: props.data.tax_liable ? '1' : '0',
+    vat_rate: props.data.vat_rate ?? 0,
+    tax_exemption_reason: props.data.tax_exemption_reason ?? '',
+    tax_exemption_note: props.data.tax_exemption_note ?? '',
+    vat_pricing_mode: props.data.vat_pricing_mode ?? 'inclusive',
+})
+
+const isLiable = computed(() => form.value.tax_liable === '1')
+const isCustomReason = computed(() => form.value.tax_exemption_reason === 'custom')
+
+const selectedReason = computed(
+    () => reasons.value.find(r => r.value === form.value.tax_exemption_reason) ?? null
+)
+
+const pricingModeLabel = computed(
+    () => pricingModes.value.find(m => m.value === form.value.vat_pricing_mode)?.label ?? '—'
+)
+
+// Vorschau des Pflichthinweises nach § 14 Abs. 4 Nr. 8 UStG, der später auf der Rechnung erscheint.
+const invoiceHint = computed(() => {
+    if (isLiable.value) {
+        return `Umsatzsteuerpflichtig – USt-Satz: ${form.value.vat_rate || 0} %`
+    }
+    if (isCustomReason.value) {
+        return form.value.tax_exemption_note?.trim() || '—'
+    }
+    return selectedReason.value?.text || '—'
+})
+
+const reasonLabel = computed(() => selectedReason.value?.label ?? '—')
+
+async function save() {
+    const saveUrl = props.data.saveEndpoint ?? '/api/v1/admin/tenant/tax'
+    const response = await request(saveUrl, {
+        method: 'POST',
+        body: {
+            tax_liable: isLiable.value,
+            vat_rate: Number(form.value.vat_rate) || 0,
+            tax_exemption_reason: isLiable.value ? null : form.value.tax_exemption_reason,
+            tax_exemption_note: form.value.tax_exemption_note,
+            vat_pricing_mode: form.value.vat_pricing_mode,
+        },
+    })
+
+    if (response && response.status === 'success') {
+        toast.success(response.message)
+        editing.value = false
+    } else {
+        toast.error(response?.message ?? 'Fehler beim Speichern')
+    }
+}
+</script>
+
+<template>
+    <div v-if="!editing">
+        <table class="data-table">
+            <tr>
+                <th>Steuerpflicht</th>
+                <td>{{ isLiable ? 'Ja – Umsatzsteuer wird erhoben' : 'Nein – umsatzsteuerbefreit' }}</td>
+            </tr>
+            <tr v-if="isLiable">
+                <th>USt-Satz</th>
+                <td>{{ form.vat_rate || 0 }} %</td>
+            </tr>
+            <tr v-if="isLiable">
+                <th>Preismodus</th>
+                <td>{{ pricingModeLabel }}</td>
+            </tr>
+            <tr v-else>
+                <th>Befreiungsgrund</th>
+                <td>{{ reasonLabel }}</td>
+            </tr>
+            <tr>
+                <th>Rechnungshinweis</th>
+                <td>{{ invoiceHint }}</td>
+            </tr>
+        </table>
+        <button class="btn-edit" @click="editing = true">Bearbeiten</button>
+    </div>
+
+    <div v-else>
+        <table class="data-table">
+            <tr>
+                <th>Steuerpflicht</th>
+                <td>
+                    <RichSelectBox v-model="form.tax_liable" :options="liableOptions"/>
+                </td>
+            </tr>
+
+            <tr v-if="isLiable">
+                <th>USt-Satz (%)</th>
+                <td><input type="number" min="0" max="100" v-model.number="form.vat_rate" class="form-input"/></td>
+            </tr>
+            <tr v-if="isLiable">
+                <th>Preismodus</th>
+                <td>
+                    <RichSelectBox v-model="form.vat_pricing_mode" :options="pricingModes"/>
+                </td>
+            </tr>
+
+            <template v-else>
+                <tr>
+                    <th>Befreiungsgrund</th>
+                    <td>
+                        <RichSelectBox
+                            v-model="form.tax_exemption_reason"
+                            :options="reasons"
+                            placeholder="Grund auswählen…"
+                        />
+                    </td>
+                </tr>
+                <tr v-if="isCustomReason">
+                    <th>Freitext</th>
+                    <td>
+                        <textarea
+                            v-model="form.tax_exemption_note"
+                            class="form-input"
+                            rows="3"
+                            placeholder="Hinweistext für die Rechnung…"
+                        ></textarea>
+                    </td>
+                </tr>
+            </template>
+
+            <tr>
+                <th>Rechnungshinweis</th>
+                <td class="hint-preview">{{ invoiceHint }}</td>
+            </tr>
+        </table>
+        <div class="btn-group">
+            <button class="btn-save" @click="save">Speichern</button>
+            <button class="btn-cancel" @click="editing = false">Abbrechen</button>
+        </div>
+    </div>
+</template>
+
+<style scoped>
+.data-table {
+    width: 100%;
+    border-collapse: collapse;
+}
+
+.data-table th {
+    text-align: left;
+    padding: 8px 12px;
+    width: 200px;
+    color: #374151;
+    border-bottom: 1px solid #e5e7eb;
+    vertical-align: top;
+}
+
+.data-table td {
+    padding: 8px 12px;
+    border-bottom: 1px solid #e5e7eb;
+}
+
+.form-input {
+    width: 100%;
+    padding: 6px 10px;
+    border: 1px solid #d1d5db;
+    border-radius: 6px;
+    font-size: 0.95rem;
+    box-sizing: border-box;
+    font-family: inherit;
+}
+
+.hint-preview {
+    color: #6b7280;
+    font-style: italic;
+}
+
+.btn-edit, .btn-save, .btn-cancel {
+    margin-top: 15px;
+    padding: 8px 20px;
+    border: none;
+    border-radius: 6px;
+    cursor: pointer;
+    font-weight: bold;
+    font-size: 0.9rem;
+}
+
+.btn-edit {
+    background-color: #1d4899;
+    color: #ffffff;
+}
+
+.btn-edit:hover {
+    background-color: #163a7a;
+}
+
+.btn-save {
+    background-color: #16a34a;
+    color: #ffffff;
+}
+
+.btn-save:hover {
+    background-color: #15803d;
+}
+
+.btn-cancel {
+    background-color: #e5e7eb;
+    color: #374151;
+    margin-left: 10px;
+}
+
+.btn-cancel:hover {
+    background-color: #d1d5db;
+}
+
+.btn-group {
+    display: flex;
+    gap: 10px;
+}
+</style>

app/Domains/Admin/Views/TenantData.vue

@@ -7,6 +7,7 @@ import TenantPayment from "./Partials/TenantPayment.vue";
 import TenantImpress from "./Partials/TenantImpress.vue";
 import TenantGdpr from "./Partials/TenantGdpr.vue";
 import TenantPaymentMethods from "./Partials/TenantPaymentMethods.vue";
+import TenantTaxInfo from "./Partials/TenantTaxInfo.vue";
 
 const props = defineProps({
     tenant: Object,
@@ -28,6 +29,11 @@ const tabs = [
         component: TenantPaymentMethods,
         endpoint: '/api/v1/admin/tenant/payment-methods',
     },
+    {
+        title: 'Steuerinformationen',
+        component: TenantTaxInfo,
+        endpoint: '/api/v1/admin/tenant/tax',
+    },
     {
         title: 'Impressum',
         component: TenantImpress,

app/Domains/Admin/Views/TenantEdit.vue

@@ -7,6 +7,7 @@ import TenantContact from "./Partials/TenantContact.vue";
 import TenantPayment from "./Partials/TenantPayment.vue";
 import TenantImpress from "./Partials/TenantImpress.vue";
 import TenantGdpr from "./Partials/TenantGdpr.vue";
+import TenantTaxInfo from "./Partials/TenantTaxInfo.vue";
 
 const props = defineProps({
     tenant: Object,
@@ -30,6 +31,11 @@ const tabs = [
         component: TenantPayment,
         endpoint: '/api/v1/admin/tenants/' + slug + '/payment',
     },
+    {
+        title: 'Steuerinformationen',
+        component: TenantTaxInfo,
+        endpoint: '/api/v1/admin/tenants/' + slug + '/tax',
+    },
     {
         title: 'Impressum',
         component: TenantImpress,

app/Domains/Event/Actions/CreateEvent/CreateEventCommand.php

@@ -47,6 +47,13 @@ class CreateEventCommand {
             'total_max_amount' => 0,
             'support_per_person' => 0,
             'support_flat' => 0,
+            // Umsatzsteuerliche Grundlage bei Anlage einfrieren (unveränderlich), damit Preisermittlung und
+            // spätere Rechnungen von späteren Tenant-Änderungen unberührt bleiben.
+            'tax_liable' => app('tenant')->tax_liable,
+            'vat_rate' => app('tenant')->vat_rate,
+            'vat_pricing_mode' => app('tenant')->vat_pricing_mode,
+            'tax_exemption_reason' => app('tenant')->tax_exemption_reason,
+            'tax_exemption_note' => app('tenant')->tax_exemption_note,
         ]);
 
         if ($event !== null) {

app/Domains/Event/Actions/SetEventAddons/SetEventAddonsCommand.php

@@ -0,0 +1,85 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetEventAddons;
+
+use App\ValueObjects\Amount;
+use Illuminate\Support\Str;
+
+class SetEventAddonsCommand
+{
+    public function __construct(private SetEventAddonsRequest $request)
+    {
+    }
+
+    public function execute(): SetEventAddonsResponse
+    {
+        $response = new SetEventAddonsResponse();
+
+        $this->request->event->addons = $this->normalize($this->request->addons);
+        $this->request->event->save();
+
+        $response->success = true;
+        return $response;
+    }
+
+    /**
+     * Normalisiert die rohe Addon-Definition: trimmt Titel/Beschreibung, parst den Preis (≥ 0), erzwingt den
+     * Titel als Pflichtfeld und generiert stabile Keys (Bestandsschutz für bereits gespeicherte Buchungen).
+     *
+     * @param array<int, array<string, mixed>> $addons
+     * @return array<int, array{key: string, title: string, description: string, price: float, flat: bool}>
+     */
+    private function normalize(array $addons): array
+    {
+        $normalized = [];
+        $usedKeys = [];
+
+        foreach ($addons as $addon) {
+            $title = trim((string)($addon['title'] ?? ''));
+            if ($title === '') {
+                continue;
+            }
+
+            $price = Amount::fromString((string)($addon['price'] ?? '0'))->getAmount();
+            if ($price < 0) {
+                $price = 0.0;
+            }
+
+            $key = $this->uniqueSlug((string)($addon['key'] ?? ''), $title, $usedKeys);
+            $usedKeys[] = $key;
+
+            $normalized[] = [
+                'key' => $key,
+                'title' => $title,
+                'description' => trim((string)($addon['description'] ?? '')),
+                'price' => round($price, 2),
+                'flat' => (bool)($addon['flat'] ?? false),
+            ];
+        }
+
+        return $normalized;
+    }
+
+    /**
+     * Liefert einen eindeutigen Slug: bevorzugt den bestehenden Wert, sonst aus dem Titel abgeleitet;
+     * Kollisionen werden durchnummeriert.
+     *
+     * @param array<int, string> $used
+     */
+    private function uniqueSlug(string $existing, string $title, array $used): string
+    {
+        $base = $existing !== '' ? $existing : Str::slug($title);
+        if ($base === '') {
+            $base = 'addon';
+        }
+
+        $candidate = $base;
+        $suffix = 2;
+        while (in_array($candidate, $used, true)) {
+            $candidate = $base . '-' . $suffix;
+            $suffix++;
+        }
+
+        return $candidate;
+    }
+}

app/Domains/Event/Actions/SetEventAddons/SetEventAddonsRequest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetEventAddons;
+
+use App\Models\Event;
+
+class SetEventAddonsRequest
+{
+    public Event $event;
+
+    /** @var array<int, array<string, mixed>> Rohe Addon-Definition aus dem Admin-Panel. */
+    public array $addons;
+
+    public function __construct(Event $event, array $addons)
+    {
+        $this->event = $event;
+        $this->addons = $addons;
+    }
+}

app/Domains/Event/Actions/SetEventAddons/SetEventAddonsResponse.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetEventAddons;
+
+class SetEventAddonsResponse
+{
+    public bool $success;
+    public ?string $message;
+
+    public function __construct()
+    {
+        $this->success = false;
+        $this->message = null;
+    }
+}

app/Domains/Event/Actions/SetParticipationOptions/SetParticipationOptionsCommand.php

@@ -0,0 +1,115 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetParticipationOptions;
+
+use Illuminate\Support\Str;
+
+class SetParticipationOptionsCommand
+{
+    public function __construct(private SetParticipationOptionsRequest $request)
+    {
+    }
+
+    public function execute(): SetParticipationOptionsResponse
+    {
+        $response = new SetParticipationOptionsResponse();
+
+        $this->request->event->participation_options = $this->normalize($this->request->questions);
+        $this->request->event->save();
+
+        $response->success = true;
+        return $response;
+    }
+
+    /**
+     * Normalisiert die rohe Fragen-Definition: trimmt Labels, generiert stabile Keys/Values und verwirft
+     * unvollständige Fragen (kein Label oder keine gültige Option). Keys/Values sind innerhalb ihres
+     * Geltungsbereichs eindeutig, damit Antworten robust referenzieren können.
+     *
+     * @param array<int, array<string, mixed>> $questions
+     * @return array<int, array{key: string, title: string, label: string, options: array<int, array{value: string, label: string}>}>
+     */
+    private function normalize(array $questions): array
+    {
+        $normalized = [];
+        $usedKeys = [];
+
+        foreach ($questions as $question) {
+            // Titel ist Pflicht (Überschrift/Feldbeschriftung); die Frage ist optionaler Erklärtext.
+            $title = trim((string)($question['title'] ?? ''));
+            if ($title === '') {
+                continue;
+            }
+
+            $label = trim((string)($question['label'] ?? ''));
+
+            $options = $this->normalizeOptions($question['options'] ?? []);
+            if ($options === []) {
+                continue;
+            }
+
+            $key = $this->uniqueSlug((string)($question['key'] ?? ''), $title, $usedKeys);
+            $usedKeys[] = $key;
+
+            $normalized[] = [
+                'key' => $key,
+                'title' => $title,
+                'label' => $label,
+                'options' => $options,
+            ];
+        }
+
+        return $normalized;
+    }
+
+    /**
+     * @param array<int, array<string, mixed>> $options
+     * @return array<int, array{value: string, label: string}>
+     */
+    private function normalizeOptions(mixed $options): array
+    {
+        if (!is_array($options)) {
+            return [];
+        }
+
+        $normalized = [];
+        $usedValues = [];
+
+        foreach ($options as $option) {
+            $label = trim((string)($option['label'] ?? ''));
+            if ($label === '') {
+                continue;
+            }
+
+            $value = $this->uniqueSlug((string)($option['value'] ?? ''), $label, $usedValues);
+            $usedValues[] = $value;
+
+            $normalized[] = ['value' => $value, 'label' => $label];
+        }
+
+        return $normalized;
+    }
+
+    /**
+     * Liefert einen eindeutigen Slug: bevorzugt den bestehenden Wert (Bestandsschutz für schon gespeicherte
+     * Fragen/Antworten), sonst aus dem Label abgeleitet; Kollisionen werden durchnummeriert.
+     *
+     * @param array<int, string> $used
+     */
+    private function uniqueSlug(string $existing, string $label, array $used): string
+    {
+        $base = $existing !== '' ? $existing : Str::slug($label);
+        if ($base === '') {
+            $base = 'option';
+        }
+
+        $candidate = $base;
+        $suffix = 2;
+        while (in_array($candidate, $used, true)) {
+            $candidate = $base . '-' . $suffix;
+            $suffix++;
+        }
+
+        return $candidate;
+    }
+}

app/Domains/Event/Actions/SetParticipationOptions/SetParticipationOptionsRequest.php

@@ -0,0 +1,19 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetParticipationOptions;
+
+use App\Models\Event;
+
+class SetParticipationOptionsRequest
+{
+    public Event $event;
+
+    /** @var array<int, array<string, mixed>> Rohe Fragen-Definition aus dem Admin-Panel. */
+    public array $questions;
+
+    public function __construct(Event $event, array $questions)
+    {
+        $this->event = $event;
+        $this->questions = $questions;
+    }
+}

app/Domains/Event/Actions/SetParticipationOptions/SetParticipationOptionsResponse.php

@@ -0,0 +1,15 @@
+<?php
+
+namespace App\Domains\Event\Actions\SetParticipationOptions;
+
+class SetParticipationOptionsResponse
+{
+    public bool $success;
+    public ?string $message;
+
+    public function __construct()
+    {
+        $this->success = false;
+        $this->message = null;
+    }
+}

app/Domains/Event/Actions/SignUp/SignUpCommand.php

@@ -27,6 +27,14 @@ class SignUpCommand {
             return $response;
         }
 
+        // Teilnahmeoptionen (event-spezifische Pflicht-Auswahl) gegen die Event-Definition absichern.
+        $participationOptionRows = $this->buildParticipationOptionRows();
+        if ($participationOptionRows === null) {
+            $response->success = false;
+            $response->message = 'Bitte alle Auswahlfelder ausfüllen.';
+            return $response;
+        }
+
         $eatingHabit = match ($this->request->eating_habit) {
             'vegan' => EatingHabit::EATING_HABIT_VEGAN,
             'vegetarian' => EatingHabit::EATING_HABIT_VEGETARIAN,
@@ -80,8 +88,89 @@ class SignUpCommand {
             ]
         );
 
+        $this->persistParticipationOptions($response->participant, $participationOptionRows);
+        $this->persistAddons($response->participant);
+
         $response->success = true;
         return $response;
     }
 
+    /**
+     * Speichert die gewählten Zusätze (Event-Addons) als Snapshot-Zeilen (Titel/Preis/Betrag) für die spätere
+     * Rechnung. Die Beträge sind bereits in der Controller-Auflösung (`resolveAddons`) berechnet, inkl. USt.
+     */
+    private function persistAddons(\App\Models\EventParticipant $participant): void
+    {
+        foreach ($this->request->addonItems as $item) {
+            $participant->selectedAddons()->create([
+                'tenant' => $this->request->event->tenant,
+                'event_id' => $this->request->event->id,
+                'addon_key' => $item['key'],
+                'title' => $item['title'],
+                'price' => $item['price'] ?? 0,
+                'flat' => (bool)($item['flat'] ?? false),
+                'days' => $item['days'] ?? 0,
+                'amount' => $item['amount'] ?? 0,
+            ]);
+        }
+    }
+
+    /**
+     * Validiert die Antworten gegen die am Event definierten Teilnahmeoptionen und erzeugt die zu speichernden
+     * Zeilen mit Label-Snapshots. Gibt null zurück, wenn eine Pflicht-Frage unbeantwortet oder eine Antwort
+     * ungültig ist (Absicherung gegen manipulierte Payloads).
+     *
+     * @return array<int, array{question_key: string, question_label: string, value: string, value_label: string}>|null
+     */
+    private function buildParticipationOptionRows(): ?array
+    {
+        $rows = [];
+
+        foreach ($this->request->event->participation_options ?? [] as $question) {
+            $key = $question['key'] ?? null;
+            if ($key === null) {
+                continue;
+            }
+
+            $value = $this->request->participationOptions[$key] ?? null;
+            if ($value === null || $value === '') {
+                return null;
+            }
+
+            $option = null;
+            foreach ($question['options'] ?? [] as $candidate) {
+                if (($candidate['value'] ?? null) === $value) {
+                    $option = $candidate;
+                    break;
+                }
+            }
+
+            if ($option === null) {
+                return null;
+            }
+
+            $rows[] = [
+                'question_key' => $key,
+                'question_label' => $question['label'] ?? $key,
+                'value' => $value,
+                'value_label' => $option['label'] ?? $value,
+            ];
+        }
+
+        return $rows;
+    }
+
+    /**
+     * @param array<int, array{question_key: string, question_label: string, value: string, value_label: string}> $rows
+     */
+    private function persistParticipationOptions(\App\Models\EventParticipant $participant, array $rows): void
+    {
+        foreach ($rows as $row) {
+            $participant->selectedOptions()->create(array_merge($row, [
+                'tenant' => $this->request->event->tenant,
+                'event_id' => $this->request->event->id,
+            ]));
+        }
+    }
+
 }

app/Domains/Event/Actions/SignUp/SignUpRequest.php

@@ -46,6 +46,10 @@ class SignUpRequest {
         public Amount $amount,
         public ?string $paymentMethod,
         public array $paymentOptions = [],
+        /** Antworten auf die Teilnahmeoptionen: [ question_key => value ]. */
+        public array $participationOptions = [],
+        /** Aufgelöste Zusätze (Event-Addons): je Eintrag [ key, title, price, flat, days, amount ]. */
+        public array $addonItems = [],
     ) {
     }
 }

app/Domains/Event/Actions/UpdateParticipant/UpdateParticipantCommand.php

@@ -72,11 +72,97 @@ class UpdateParticipantCommand {
 
 
         $p->save();
+
+        if ($this->request->participationOptions !== null) {
+            $this->syncParticipationOptions($p);
+        }
+
+        if ($this->request->selectedAddons !== null) {
+            $this->syncAddons($p);
+        }
+
         $this->response->success = true;
         $this->response->participant = $p;
         return $this->response;
     }
 
+    /**
+     * Ersetzt die zugeordneten Zusätze (Event-Addons) anhand der Auswahl. Bewusst **ohne Preis/Betrag**
+     * (amount 0): der Teilnahmebeitrag wird in den Details ohnehin manuell gesetzt. Es wird nur der Titel als
+     * Snapshot gespeichert, damit die Zuordnung sichtbar bleibt.
+     */
+    private function syncAddons(EventParticipant $participant): void
+    {
+        $participant->selectedAddons()->delete();
+
+        $selection = $this->request->selectedAddons ?? [];
+
+        foreach ($participant->event?->addons ?? [] as $addon) {
+            $key = $addon['key'] ?? null;
+            if ($key === null || empty($selection[$key])) {
+                continue;
+            }
+
+            $participant->selectedAddons()->create([
+                'tenant' => $participant->tenant,
+                'event_id' => $participant->event_id,
+                'addon_key' => $key,
+                'title' => $addon['title'] ?? $key,
+                'price' => 0,
+                'flat' => (bool)($addon['flat'] ?? false),
+                'days' => 0,
+                'amount' => 0,
+            ]);
+        }
+    }
+
+    /**
+     * Ersetzt die zugeordneten Teilnahmeoptionen anhand der übergebenen Antworten. Nachträgliche Zuordnung im
+     * Back-Office ist lückenlos möglich: nur gegen die Event-Definition gültige Antworten werden gespeichert,
+     * leere/entfallene Antworten werden abgeräumt. Frage-/Options-Label werden als Snapshot mitgeschrieben.
+     */
+    private function syncParticipationOptions(EventParticipant $participant): void
+    {
+        $participant->selectedOptions()->delete();
+
+        $answers = $this->request->participationOptions ?? [];
+
+        foreach ($participant->event?->participation_options ?? [] as $question) {
+            $key = $question['key'] ?? null;
+            if ($key === null) {
+                continue;
+            }
+
+            $value = $answers[$key] ?? null;
+            if ($value === null || $value === '') {
+                continue;
+            }
+
+            $option = null;
+            foreach ($question['options'] ?? [] as $candidate) {
+                if (($candidate['value'] ?? null) === $value) {
+                    $option = $candidate;
+                    break;
+                }
+            }
+
+            if ($option === null) {
+                continue;
+            }
+
+            $label = trim((string)($question['label'] ?? ''));
+
+            $participant->selectedOptions()->create([
+                'tenant' => $participant->tenant,
+                'event_id' => $participant->event_id,
+                'question_key' => $key,
+                'question_label' => $label !== '' ? $label : ($question['title'] ?? $key),
+                'value' => $value,
+                'value_label' => $option['label'] ?? $value,
+            ]);
+        }
+    }
+
     private function handleAmountChanges(EventParticipant $participant) {
         $this->response->amountPaid = $participant->amount_paid;
         $this->response->amountExpected = $participant->amount;

app/Domains/Event/Actions/UpdateParticipant/UpdateParticipantRequest.php

@@ -36,5 +36,9 @@ class UpdateParticipantRequest {
         public string $amountPaid,
         public string $amountExpected,
         public string $cocStatus,
+        /** Antworten auf die Teilnahmeoptionen: [ question_key => value ]. null = unverändert lassen. */
+        public ?array $participationOptions = null,
+        /** Gewählte Zusätze: [ addon_key => bool ]. null = unverändert lassen. */
+        public ?array $selectedAddons = null,
     ) {}
 }

app/Domains/Event/Controllers/DetailsController.php

@@ -2,8 +2,12 @@
 
 namespace App\Domains\Event\Controllers;
 
+use App\Domains\Event\Actions\SetEventAddons\SetEventAddonsCommand;
+use App\Domains\Event\Actions\SetEventAddons\SetEventAddonsRequest;
 use App\Domains\Event\Actions\SetParticipationFees\SetParticipationFeesCommand;
 use App\Domains\Event\Actions\SetParticipationFees\SetParticipationFeesRequest;
+use App\Domains\Event\Actions\SetParticipationOptions\SetParticipationOptionsCommand;
+use App\Domains\Event\Actions\SetParticipationOptions\SetParticipationOptionsRequest;
 use App\Domains\Event\Actions\SetPaymentMethods\SetPaymentMethodsCommand;
 use App\Domains\Event\Actions\SetPaymentMethods\SetPaymentMethodsRequest;
 use App\Domains\Event\Actions\UpdateEvent\UpdateEventCommand;
@@ -142,6 +146,28 @@ class DetailsController extends CommonController {
         return response()->json(['status' => $response->success ? 'success' : 'error']);
     }
 
+    public function updateParticipationOptions(int $eventId, Request $request): JsonResponse
+    {
+        $event = $this->events->getById($eventId);
+
+        $setRequest = new SetParticipationOptionsRequest($event, (array)$request->input('questions', []));
+        $setCommand = new SetParticipationOptionsCommand($setRequest);
+        $response = $setCommand->execute();
+
+        return response()->json(['status' => $response->success ? 'success' : 'error', 'message' => $response->message]);
+    }
+
+    public function updateEventAddons(int $eventId, Request $request): JsonResponse
+    {
+        $event = $this->events->getById($eventId);
+
+        $setRequest = new SetEventAddonsRequest($event, (array)$request->input('addons', []));
+        $setCommand = new SetEventAddonsCommand($setRequest);
+        $response = $setCommand->execute();
+
+        return response()->json(['status' => $response->success ? 'success' : 'error', 'message' => $response->message]);
+    }
+
     public function downloadPdfList(string $eventId, string $listType, Request $request): Response
     {
         $event = $this->events->getByIdentifier($eventId);
@@ -195,6 +221,12 @@ class DetailsController extends CommonController {
             case 'by-participation-group':
                 $participants = $this->eventParticipants->groupByParticipationType($event, $request);
                 break;
+            case 'by-participation-option':
+                $participants = $this->eventParticipants->groupByParticipationOption($event, $request);
+                break;
+            case 'by-addon':
+                $participants = $this->eventParticipants->groupByAddon($event, $request);
+                break;
             case 'signed-off':
                 $participants = $this->eventParticipants->getSignedOffParticipants($event, $request);
                 break;

app/Domains/Event/Controllers/MailCompose/ByGroupController.php

@@ -19,6 +19,10 @@ class ByGroupController extends CommonController
                 $participants = $this->eventParticipants->groupByParticipationType($event, $request, $request->input('groupName'));
                 $recipients = $this->eventParticipants->getMailAddresses($participants[$request->input('groupName')]);
                 break;
+            case 'by-participation-option':
+                $participants = $this->eventParticipants->groupByParticipationOption($event, $request, $request->input('groupName'));
+                $recipients = $this->eventParticipants->getMailAddresses($participants[$request->input('groupName')] ?? []);
+                break;
             case 'signed-off':
                 $participants = $this->eventParticipants->getSignedOffParticipants($event, $request, $request->input('groupName'));
                 $recipients = $this->eventParticipants->getMailAddresses($participants[$request->input('groupName')]);

app/Domains/Event/Controllers/ParticipantUpdateController.php

@@ -44,6 +44,8 @@ class ParticipantUpdateController extends CommonController {
             amountPaid: $request->input('amountPaid'),
             amountExpected: $request->input('amountExpected'),
             cocStatus: $request->input('cocStatus'),
+            participationOptions: $request->has('participationOptions') ? (array)$request->input('participationOptions') : null,
+            selectedAddons: $request->has('selectedAddons') ? (array)$request->input('selectedAddons') : null,
         );
 
         $command = new UpdateParticipantCommand($updateRequest);

app/Domains/Event/Controllers/SignupController.php

@@ -12,6 +12,7 @@ use App\Providers\DoubleCheckEventRegistrationProvider;
 use App\Providers\InertiaProvider;
 use App\Resources\UserResource;
 use App\Scopes\CommonController;
+use App\ValueObjects\Amount;
 use DateTime;
 use Illuminate\Http\JsonResponse;
 use Illuminate\Http\Request;
@@ -104,6 +105,11 @@ class SignupController extends CommonController {
             $siblingReduction
         );
 
+        // Gewählte Zusätze (Event-Addons) auflösen und auf den Gesamtbetrag aufaddieren.
+        $selectedAddonKeys = array_keys(array_filter((array)$request->input('addons', []), fn($v) => (bool)$v));
+        $addonResolution = $eventResource->resolveAddons($selectedAddonKeys, $arrival, $departure);
+        $amount->addAmount($addonResolution['total']);
+
         $signupRequest = new SignUpRequest(
             $event,
             $registrationData['userId'] ?? null,
@@ -142,6 +148,8 @@ class SignupController extends CommonController {
             $amount,
             $registrationData['paymentMethod'] ?? null,
             (array)($registrationData['paymentOptions'] ?? []),
+            (array)($registrationData['participationOptions'] ?? []),
+            $addonResolution['items'],
         );
 
         $signupCommand = new SignUpCommand($signupRequest);
@@ -184,18 +192,41 @@ class SignupController extends CommonController {
 
         $siblingReduction = $request->input('sibling') === 'true';
 
-        $amount = $event->calculateAmount(
+        $arrival = \DateTime::createFromFormat('Y-m-d', $request->input('arrival'));
+        $departure = \DateTime::createFromFormat('Y-m-d', $request->input('departure'));
+
+        $baseFee = $event->calculateAmount(
             $request->input('participationType'),
             $request->input('beitrag'),
-            \DateTime::createFromFormat('Y-m-d', $request->input('arrival')),
+            $arrival,
-            \DateTime::createFromFormat('Y-m-d', $request->input('departure')),
+            $departure,
             $siblingReduction
         );
 
+        // Gewählte Zusätze immer einrechnen -- so enthält der finale Anzeigebetrag (und der Bestätigungstext)
+        // stets die Addons und der Zahlungsschritt wird nur bei Gesamt 0 € übersprungen.
+        $selectedAddonKeys = array_keys(array_filter((array)$request->input('addons', []), fn($v) => (bool)$v));
+        $resolution = $event->resolveAddons($selectedAddonKeys, $arrival, $departure);
+
+        // Gesamt = Teilnahmebeitrag + Zusätze; Basisbetrag separat für die Kostenübersicht in der Zusammenfassung.
+        $total = new Amount($baseFee->getAmount(), 'Euro');
+        $total->addAmount($resolution['total']);
+
+        $addonLines = array_map(fn($item) => [
+            'key' => $item['key'],
+            'title' => $item['title'],
+            'amountValue' => $item['amount'],
+            'amount' => new Amount($item['amount'], 'Euro')->toString(),
+            'free' => $item['amount'] <= 0,
+        ], $resolution['items']);
+
         // amountValue (numerisch) steuert im Frontend das Überspringen des Zahlungsart-Schritts bei 0 €.
         return response()->json([
-            'amount' => $amount->toString(),
+            'amount' => $total->toString(),
-            'amountValue' => $amount->getAmount(),
+            'amountValue' => $total->getAmount(),
+            'baseAmount' => $baseFee->toString(),
+            'baseAmountValue' => $baseFee->getAmount(),
+            'addons' => $addonLines,
         ]);
     }
 }

app/Domains/Event/Routes/api.php

@@ -46,6 +46,8 @@ Route::prefix('api/v1')
                         Route::post('/participation-fees', [DetailsController::class, 'updateParticipationFees']);
                         Route::post('/common-settings', [DetailsController::class, 'updateCommonSettings']);
                         Route::post('/payment-methods', [DetailsController::class, 'updatePaymentMethods']);
+                        Route::post('/participation-options', [DetailsController::class, 'updateParticipationOptions']);
+                        Route::post('/event-addons', [DetailsController::class, 'updateEventAddons']);
                     });
 
 

app/Domains/Event/Views/Details.vue

@@ -1,9 +1,11 @@
 <script setup>
-import {reactive, inject, onMounted} from 'vue';
+import {onMounted} from 'vue';
 import AppLayout from "../../../../resources/js/layouts/AppLayout.vue";
 import ShadowedBox from "../../../Views/Components/ShadowedBox.vue";
 import TabbedPage from "../../../Views/Components/TabbedPage.vue";
 import ParticipantsList from "./Partials/ParticipantsList.vue";
+import ParticipantsByOption from "./Partials/ParticipantsByOption.vue";
+import ParticipantsByAddon from "./Partials/ParticipantsByAddon.vue";
 import Overview from "./Partials/Overview.vue";
 
 const props = defineProps({
@@ -31,16 +33,21 @@ const tabs = [
         component: ParticipantsList,
         endpoint: "/api/v1/event/details/" + props.event.identifier + '/participants/by-participation-group',
     },
+    {
+        title: 'Teilis nach Teilnahmeoption',
+        component: ParticipantsByOption,
+        endpoint: "/api/v1/event/details/" + props.event.identifier + '/participants/by-participation-option',
+    },
+    {
+        title: 'Teilis mit Zusatzoptionen',
+        component: ParticipantsByAddon,
+        endpoint: "/api/v1/event/details/" + props.event.identifier + '/participants/by-addon',
+    },
     {
         title: 'Abgemeldete Teilis',
         component: ParticipantsList,
         endpoint: "/api/v1/event/details/" + props.event.identifier + '/participants/signed-off',
     },
-    {
-        title: 'Zusätze',
-        component: ParticipantsList,
-        endpoint: "/api/v1/cost-unit/open/archived-cost-units",
-    },
 ]
 
 onMounted(() => {

app/Domains/Event/Views/Partials/EventAddons.vue

@@ -0,0 +1,166 @@
+<script setup>
+import {ref} from "vue";
+import {toast} from "vue3-toastify";
+import {request} from "../../../../../resources/js/components/HttpClient.js";
+import AmountInput from "../../../../Views/Components/AmountInput.vue";
+
+const emit = defineEmits(['close'])
+
+const props = defineProps({
+    event: Object,
+})
+
+// Addon-Definition dieses Events: [ { key, title, description, price, flat } ].
+// key bleibt für bestehende Einträge erhalten (Bestandsschutz für bereits gebuchte Zusätze).
+const addons = ref((props.event.addons ?? []).map(a => ({
+    key: a.key ?? '',
+    title: a.title ?? '',
+    description: a.description ?? '',
+    price: a.price != null ? String(a.price).replace('.', ',') : '0',
+    flat: a.flat ?? false,
+})))
+
+function addAddon() {
+    addons.value.push({key: '', title: '', description: '', price: '0', flat: true})
+}
+
+function removeAddon(index) {
+    addons.value.splice(index, 1)
+}
+
+function validate() {
+    for (const addon of addons.value) {
+        if (addon.title.trim() === '') {
+            toast.error('Bitte für jeden Zusatz einen Titel angeben.')
+            return false
+        }
+    }
+
+    return true
+}
+
+async function save() {
+    if (!validate()) {
+        return
+    }
+
+    const response = await request('/api/v1/event/details/' + props.event.id + '/event-addons', {
+        method: 'POST',
+        body: {
+            addons: addons.value,
+        }
+    })
+
+    if (response.status !== 'success') {
+        toast.error(response.message ?? 'Die Zusatzoptionen konnten nicht gespeichert werden.')
+        return
+    }
+
+    toast.success('Die Zusatzoptionen wurden gespeichert')
+    emit('close')
+}
+</script>
+
+<template>
+    <div class="event-addons">
+        <h3>Zusatzoptionen</h3>
+        <p style="color: #6b7280; font-size: 0.9rem;">
+            Buchbare Zusätze zur Veranstaltung (z. B. Parkticket, Aufnäher). Jede Position ist eine Ja/Nein-Auswahl.
+            Preis 0 wird dem Teilnehmenden als „Kostenfrei" angezeigt. Ist „Pauschale" nicht gesetzt, wird der Preis
+            mit der Anzahl der Teilnahmetage multipliziert. Ohne Zusätze wird dieser Schritt in der Anmeldung
+            übersprungen.
+        </p>
+
+        <div v-for="(addon, index) in addons" :key="index" class="addon-card">
+            <div class="addon-head">
+                <div class="addon-fields">
+                    <label class="field-label">Titel</label>
+                    <input type="text" v-model="addon.title" class="width-full" placeholder="z. B. „Parkticket“"/>
+
+                    <label class="field-label">Beschreibung (optional)</label>
+                    <input type="text" v-model="addon.description" class="width-full" placeholder="Kurze Erläuterung"/>
+
+                    <div class="addon-price-row">
+                        <span>
+                            <label class="field-label">Preis</label>
+                            <AmountInput v-model="addon.price" class="width-small"/> Euro
+                        </span>
+                        <label class="flat-label">
+                            <input type="checkbox" v-model="addon.flat"/>
+                            Pauschale (nicht pro Tag)
+                        </label>
+                    </div>
+                </div>
+                <label class="link remove-link" @click="removeAddon(index)">Entfernen</label>
+            </div>
+        </div>
+
+        <div style="margin-top: 16px;">
+            <label class="link" @click="addAddon">+ Zusatz hinzufügen</label>
+        </div>
+
+        <div style="margin-top: 24px;">
+            <input type="button" value="Speichern" @click="save"/>
+        </div>
+    </div>
+</template>
+
+<style scoped>
+.addon-card {
+    margin-top: 16px;
+    padding: 14px;
+    background: #f8fafc;
+    border: 1px solid #e5e7eb;
+    border-radius: 10px;
+}
+
+.addon-head {
+    display: flex;
+    align-items: flex-start;
+    gap: 12px;
+}
+
+.addon-fields {
+    flex: 1;
+}
+
+.field-label {
+    display: block;
+    font-size: 0.78rem;
+    color: #6b7280;
+    margin: 6px 0 2px;
+}
+
+.addon-fields .field-label:first-child {
+    margin-top: 0;
+}
+
+.addon-price-row {
+    display: flex;
+    align-items: flex-end;
+    gap: 24px;
+    margin-top: 6px;
+}
+
+.flat-label {
+    display: flex;
+    align-items: center;
+    gap: 6px;
+    font-size: 0.9rem;
+    color: #374151;
+}
+
+.width-full {
+    width: 100%;
+}
+
+.width-small {
+    width: 90px;
+}
+
+.remove-link {
+    white-space: nowrap;
+    color: #ef4444;
+    font-size: 0.85rem;
+}
+</style>

app/Domains/Event/Views/Partials/Overview.vue

@@ -1,6 +1,8 @@
 <script setup>
 import {onMounted, reactive, ref} from "vue";
 import ParticipationFees from "./ParticipationFees.vue";
+import ParticipationOptions from "./ParticipationOptions.vue";
+import EventAddons from "./EventAddons.vue";
 import ParticipationSummary from "./ParticipationSummary.vue";
 import CommonSettings from "./CommonSettings.vue";
 import EventManagement from "./EventManagement.vue";
@@ -36,6 +38,14 @@
         displayData.value = 'participationFees';
     }
 
+    async function showParticipationOptions() {
+        displayData.value = 'participationOptions';
+    }
+
+async function showEventAddons() {
+    displayData.value = 'eventAddons';
+}
+
     async function showEventManagement() {
         displayData.value = 'eventManagement';
     }
@@ -107,6 +117,9 @@
 
 
     <ParticipationFees v-if="displayData === 'participationFees'" :event="dynamicProps.event"  @close="showMain" />
+    <ParticipationOptions v-else-if="displayData === 'participationOptions'" :event="dynamicProps.event"
+                          @close="showMain"/>
+    <EventAddons v-else-if="displayData === 'eventAddons'" :event="dynamicProps.event" @close="showMain"/>
     <CommonSettings v-else-if="displayData === 'commonSettings'" :event="dynamicProps.event"  @close="showMain" />
     <EventManagement v-else-if="displayData === 'eventManagement'" :event="dynamicProps.event"  @close="showMain" />
 
@@ -185,7 +198,10 @@
         <div class="event-flexbox-row bottom">
             <label style="font-size: 9pt;" class="link" @click="showCommonSettings">Allgemeine Einstellungen</label> &nbsp;
             <label style="font-size: 9pt;" class="link" @click="showEventManagement">Veranstaltungsleitung</label> &nbsp;
-            <label style="font-size: 9pt;" class="link" @click="showParticipationFees">Teilnahmegebühren</label>
+            <label style="font-size: 9pt;" class="link" @click="showParticipationFees">Teilnahmegebühren</label> &nbsp;
+            <label style="font-size: 9pt;" class="link" @click="showParticipationOptions">Teilnahmeoptionen</label>
+            &nbsp;
+            <label style="font-size: 9pt;" class="link" @click="showEventAddons">Zusatzoptionen</label>
             <a style="font-size: 9pt;" class="link" :href="'/budget/' + props.data.event.costUnit.id">Budget bearbeiten</a>
             <a style="font-size: 9pt;" class="link" :href="'/cost-unit/' + props.data.event.costUnit.id">Ausgabenübersicht</a>
             <a v-if="!dynamicProps.event.registrationAllowed && !dynamicProps.event.archived" style="color: #ff0000; font-size: 9pt;" class="link" @click="archiveEvent">Archivieren</a>

app/Domains/Event/Views/Partials/ParticipantData.vue

@@ -1,5 +1,5 @@
 <script setup>
-import {onMounted, reactive, watch} from "vue";
+import {computed, onMounted, reactive, watch} from "vue";
 import AmountInput from "../../../../Views/Components/AmountInput.vue";
 import DialableTelephoneNumber from "../../../../Views/Components/DialableTelephoneNumber.vue";
 
@@ -60,8 +60,27 @@ const form = reactive({
     amountPaid: '',
     amountExpected: '',
     cocStatus: '',
+    participationOptions: {},
+    selectedAddons: {},
 });
 
+// Teilnahmeoptionen des Events (Definition mit Titel/Frage/Optionen).
+const participationQuestions = computed(() => staticProps.event?.participationOptions ?? []);
+
+// Zusatzoptionen (Event-Addons) des Events.
+const eventAddons = computed(() => staticProps.event?.addons ?? []);
+
+// Gewählte Antwort (Options-Label) eines Teilnehmers zu einer Frage – für die Ansicht „Titel: Antwort".
+function answerLabelFor(questionKey) {
+    const answer = (props.participant?.participationOptions ?? []).find(o => o.questionKey === questionKey);
+    return answer?.valueLabel ?? '—';
+}
+
+// Hat der Teilnehmer diesen Zusatz gebucht? – für die Ansicht.
+function isAddonSelected(addonKey) {
+    return (props.participant?.selectedAddons ?? []).some(a => a.addonKey === addonKey);
+}
+
 watch(
     () => props.participant,
     (participant) => {
@@ -94,6 +113,12 @@ watch(
         form.amountPaid = participant?.amountPaid.short ?? '';
         form.amountExpected = participant?.amountExpected.short ?? '';
         form.cocStatus = participant?.efz_status ?? '';
+        form.participationOptions = Object.fromEntries(
+            (participant?.participationOptions ?? []).map(o => [o.questionKey, o.value])
+        );
+        form.selectedAddons = Object.fromEntries(
+            (participant?.selectedAddons ?? []).map(a => [a.addonKey, true])
+        );
     },
     { immediate: true }
 );
@@ -388,6 +413,43 @@ function saveParticipant() {
                 </table>
             </div>
         </div>
+
+        <div class="participationData" v-if="participationQuestions.length > 0 || eventAddons.length > 0">
+            <div>
+                <template v-if="participationQuestions.length > 0">
+                    <h3>Teilnahmeoptionen</h3>
+                    <table>
+                        <tr v-for="question in participationQuestions" :key="question.key">
+                            <th>{{ question.title || question.label }}</th>
+                            <td>
+                                <span v-if="!staticProps.editMode">{{ answerLabelFor(question.key) }}</span>
+                                <select v-else v-model="form.participationOptions[question.key]">
+                                    <option value="">— keine —</option>
+                                    <option v-for="option in question.options" :key="option.value"
+                                            :value="option.value">
+                                        {{ option.label }}
+                                    </option>
+                                </select>
+                            </td>
+                        </tr>
+                    </table>
+                </template>
+            </div>
+            <div>
+                <template v-if="eventAddons.length > 0">
+                    <h3>Zusatzoptionen</h3>
+                    <table>
+                        <tr v-for="addon in eventAddons" :key="addon.key">
+                            <th>{{ addon.title }}</th>
+                            <td>
+                                <span v-if="!staticProps.editMode">{{ isAddonSelected(addon.key) ? 'Ja' : '—' }}</span>
+                                <input v-else type="checkbox" v-model="form.selectedAddons[addon.key]"/>
+                            </td>
+                        </tr>
+                    </table>
+                </template>
+            </div>
+        </div>
     </div>
 
     <button v-if="!staticProps.editMode" class="button" @click="enableEditMode">Bearbeiten</button>
@@ -407,6 +469,10 @@ function saveParticipant() {
     gap: 20px;
 }
 
+.participationData table tr th {
+    width: 200px;
+}
+
 .participationData div {
     flex: 1;
     vertical-align: top;

app/Domains/Event/Views/Partials/ParticipantsByAddon.vue

@@ -0,0 +1,67 @@
+<script setup>
+import {computed, inject} from "vue";
+import ParticipantsList from "./ParticipantsList.vue";
+
+const props = defineProps({
+    data: {
+        type: Object,
+        default: () => ({participants: {}, event: {}, listType: ''}),
+    },
+});
+
+// Von TabbedPage bereitgestellt: erlaubt den Sprung zum Übersicht-Tab (Index 0), wo die
+// Zusatzoptionen konfiguriert werden.
+const selectTab = inject('selectTab', null);
+
+const hasAddons = computed(() => (props.data?.event?.addons?.length ?? 0) > 0);
+
+function goToOverview() {
+    if (selectTab) {
+        selectTab(0);
+    }
+}
+</script>
+
+<template>
+    <ParticipantsList v-if="hasAddons" :data="data" :show-group-mail="false"/>
+
+    <div v-else class="no-addons">
+        <h3>Keine Zusatzoptionen angelegt</h3>
+        <p>
+            Für diese Veranstaltung sind noch keine Zusatzoptionen angelegt. Sobald du unter
+            <strong>Übersicht → Zusatzoptionen</strong> Zusätze definierst, werden die Teilnehmenden hier nach
+            ihren gebuchten Zusätzen gruppiert.
+        </p>
+        <button v-if="selectTab" type="button" class="button" @click="goToOverview">
+            Zu den Zusatzoptionen
+        </button>
+    </div>
+</template>
+
+<style scoped>
+.no-addons {
+    max-width: 640px;
+    margin: 20px auto;
+    padding: 24px;
+    background: #f8fafc;
+    border: 1px solid #e5e7eb;
+    border-radius: 10px;
+    text-align: center;
+}
+
+.no-addons p {
+    color: #4b5563;
+    line-height: 1.6;
+}
+
+.button {
+    margin-top: 12px;
+    padding: 8px 18px;
+    background: #2563eb;
+    color: #fff;
+    border: none;
+    border-radius: 8px;
+    font-weight: 600;
+    cursor: pointer;
+}
+</style>

app/Domains/Event/Views/Partials/ParticipantsByOption.vue

@@ -0,0 +1,67 @@
+<script setup>
+import {computed, inject} from "vue";
+import ParticipantsList from "./ParticipantsList.vue";
+
+const props = defineProps({
+    data: {
+        type: Object,
+        default: () => ({participants: {}, event: {}, listType: ''}),
+    },
+});
+
+// Von TabbedPage bereitgestellt: erlaubt den Sprung zum Übersicht-Tab (Index 0), wo die
+// Teilnahmeoptionen konfiguriert werden.
+const selectTab = inject('selectTab', null);
+
+const hasOptions = computed(() => (props.data?.event?.participationOptions?.length ?? 0) > 0);
+
+function goToOverview() {
+    if (selectTab) {
+        selectTab(0);
+    }
+}
+</script>
+
+<template>
+    <ParticipantsList v-if="hasOptions" :data="data" :show-group-mail="false"/>
+
+    <div v-else class="no-options">
+        <h3>Keine Teilnahmeoptionen angelegt</h3>
+        <p>
+            Für diese Veranstaltung sind noch keine Teilnahmeoptionen angelegt. Sobald du unter
+            <strong>Übersicht → Teilnahmeoptionen</strong> Fragen definierst, werden die Teilnehmenden hier nach
+            ihrer Auswahl gruppiert.
+        </p>
+        <button v-if="selectTab" type="button" class="button" @click="goToOverview">
+            Zu den Teilnahmeoptionen
+        </button>
+    </div>
+</template>
+
+<style scoped>
+.no-options {
+    max-width: 640px;
+    margin: 20px auto;
+    padding: 24px;
+    background: #f8fafc;
+    border: 1px solid #e5e7eb;
+    border-radius: 10px;
+    text-align: center;
+}
+
+.no-options p {
+    color: #4b5563;
+    line-height: 1.6;
+}
+
+.button {
+    margin-top: 12px;
+    padding: 8px 18px;
+    background: #2563eb;
+    color: #fff;
+    border: none;
+    border-radius: 8px;
+    font-weight: 600;
+    cursor: pointer;
+}
+</style>

app/Domains/Event/Views/Partials/ParticipantsList.vue

@@ -20,6 +20,11 @@ const props = defineProps({
             listType: '',
         }),
     },
+    // Steuert, ob je Gruppe der „E-Mail an Gruppe senden"-Button angezeigt wird.
+    showGroupMail: {
+        type: Boolean,
+        default: true,
+    },
 });
 
 const today = format(new Date(), "yyyy-MM-dd");
@@ -404,7 +409,8 @@ function mailToGroup(groupKey) {
                         27 Jahre und älter: <strong>{{ getAgeCounts(participants)['27+'] ?? 0 }}</strong>
                     </td>
                     <td class="pl-summary-action">
-                        <input type="button" class="button" @click="mailToGroup(groupKey)" value="E-Mail an Gruppe senden" />
+                        <input v-if="showGroupMail" type="button" class="button" @click="mailToGroup(groupKey)"
+                               value="E-Mail an Gruppe senden"/>
                     </td>
                 </tr>
                 </tbody>

app/Domains/Event/Views/Partials/ParticipationOptions.vue

@@ -0,0 +1,182 @@
+<script setup>
+import {ref} from "vue";
+import {toast} from "vue3-toastify";
+import {request} from "../../../../../resources/js/components/HttpClient.js";
+
+const emit = defineEmits(['close'])
+
+const props = defineProps({
+    event: Object,
+})
+
+// Fragen-Definition dieses Events: [ { key, label, options: [ { value, label } ] } ].
+// key/value bleiben für bestehende Einträge erhalten (Bestandsschutz für bereits gespeicherte Antworten);
+// neue Einträge bekommen serverseitig beim Speichern einen stabilen Slug.
+const questions = ref((props.event.participationOptions ?? []).map(q => ({
+    key: q.key ?? '',
+    title: q.title ?? '',
+    label: q.label ?? '',
+    options: (q.options ?? []).map(o => ({value: o.value ?? '', label: o.label ?? ''})),
+})))
+
+function addQuestion() {
+    questions.value.push({key: '', title: '', label: '', options: [{value: '', label: ''}, {value: '', label: ''}]})
+}
+
+function removeQuestion(index) {
+    questions.value.splice(index, 1)
+}
+
+function addOption(question) {
+    question.options.push({value: '', label: ''})
+}
+
+function removeOption(question, index) {
+    question.options.splice(index, 1)
+}
+
+function validate() {
+    for (const question of questions.value) {
+        if (question.title.trim() === '') {
+            toast.error('Bitte für jede Frage einen Titel angeben.')
+            return false
+        }
+
+        const validOptions = question.options.filter(o => o.label.trim() !== '')
+        if (validOptions.length < 1) {
+            toast.error('Jede Frage braucht mindestens eine Auswahlmöglichkeit.')
+            return false
+        }
+    }
+
+    return true
+}
+
+async function save() {
+    if (!validate()) {
+        return
+    }
+
+    const response = await request('/api/v1/event/details/' + props.event.id + '/participation-options', {
+        method: 'POST',
+        body: {
+            questions: questions.value,
+        }
+    })
+
+    if (response.status !== 'success') {
+        toast.error(response.message ?? 'Die Teilnahmeoptionen konnten nicht gespeichert werden.')
+        return
+    }
+
+    toast.success('Die Teilnahmeoptionen wurden gespeichert')
+    emit('close')
+}
+</script>
+
+<template>
+    <div class="participation-options">
+        <h3>Teilnahmeoptionen</h3>
+        <p style="color: #6b7280; font-size: 0.9rem;">
+            Pflicht-Auswahlfragen für die Anmeldung (z. B. Kurs oder Stufe). Je Frage ist genau eine Option wählbar.
+            Ohne Fragen wird dieser Schritt in der Anmeldung übersprungen.
+        </p>
+
+        <div v-for="(question, qIndex) in questions" :key="qIndex" class="question-card">
+            <div class="question-head">
+                <div class="question-fields">
+                    <label class="field-label">Titel (Überschrift / Feldbeschriftung)</label>
+                    <input
+                        type="text"
+                        v-model="question.title"
+                        class="width-full"
+                        placeholder="Titel, z. B. „Kurs“"
+                    />
+
+                    <label class="field-label">Frage / Erklärtext (optional)</label>
+                    <input
+                        type="text"
+                        v-model="question.label"
+                        class="width-full"
+                        placeholder="z. B. „Welchen Kurs möchtest du belegen?“"
+                    />
+                </div>
+                <label class="link remove-link" @click="removeQuestion(qIndex)">Frage entfernen</label>
+            </div>
+
+            <div class="options">
+                <div v-for="(option, oIndex) in question.options" :key="oIndex" class="option-row">
+                    <input
+                        type="text"
+                        v-model="option.label"
+                        class="width-full"
+                        placeholder="Auswahlmöglichkeit"
+                    />
+                    <label class="link remove-link" @click="removeOption(question, oIndex)">✕</label>
+                </div>
+                <label class="link" @click="addOption(question)">+ Option hinzufügen</label>
+            </div>
+        </div>
+
+        <div style="margin-top: 16px;">
+            <label class="link" @click="addQuestion">+ Frage hinzufügen</label>
+        </div>
+
+        <div style="margin-top: 24px;">
+            <input type="button" value="Speichern" @click="save"/>
+        </div>
+    </div>
+</template>
+
+<style scoped>
+.question-card {
+    margin-top: 16px;
+    padding: 14px;
+    background: #f8fafc;
+    border: 1px solid #e5e7eb;
+    border-radius: 10px;
+}
+
+.question-head {
+    display: flex;
+    align-items: flex-start;
+    gap: 12px;
+}
+
+.question-fields {
+    flex: 1;
+}
+
+.field-label {
+    display: block;
+    font-size: 0.78rem;
+    color: #6b7280;
+    margin: 6px 0 2px;
+}
+
+.question-fields .field-label:first-child {
+    margin-top: 0;
+}
+
+.options {
+    margin-top: 12px;
+    padding-left: 12px;
+}
+
+.option-row {
+    display: flex;
+    align-items: center;
+    gap: 10px;
+    margin-bottom: 8px;
+}
+
+.width-full {
+    width: 100%;
+}
+
+.remove-link {
+    white-space: nowrap;
+    color: #ef4444;
+    font-size: 0.85rem;
+}
+</style>

app/Domains/Event/Views/Partials/SignUpForm/SignupForm.vue

@@ -6,6 +6,7 @@ import StepPersonalData from './steps/StepPersonalData.vue'
 import StepRegistrationMode from './steps/StepRegistrationMode.vue'
 import StepArrival from './steps/StepArrival.vue'
 import StepAddons from './steps/StepAddons.vue'
+import StepParticipationOptions from './steps/StepParticipationOptions.vue'
 import StepPhotoPermissions from './steps/StepPhotoPermissions.vue'
 import StepAllergies from './steps/StepAllergies.vue'
 import StepPaymentMethod from './steps/StepPaymentMethod.vue'
@@ -23,7 +24,8 @@ const emit = defineEmits(['registrationDone'])
 
 const {
     currentStep, goToStep, formData, selectedAddons,
-    submit, submitting, submitResult, summaryLoading, summaryAmount, summaryAmountValue
+    submit, submitting, submitResult, summaryLoading, summaryAmount, summaryAmountValue,
+    summaryBaseAmount, summaryAddonLines
 } = useSignupForm(props.event, props.participantData)
 
 const steps = [
@@ -33,10 +35,11 @@ const steps = [
     { step: 4, label: 'An-/Abreise' },
     { step: 5, label: 'Teilnahmegruppe' },
     { step: 6, label: 'Zusatzoptionen' },
-    { step: 7, label: 'Fotoerlaubnis' },
+    {step: 7, label: 'Teilnahmeoptionen'},
-    { step: 8, label: 'Allergien' },
+    {step: 8, label: 'Fotoerlaubnis'},
-    {step: 9, label: 'Zahlungsart'},
+    {step: 9, label: 'Allergien'},
-    {step: 10, label: 'Zusammenfassung'},
+    {step: 10, label: 'Zahlungsart'},
+    {step: 11, label: 'Zusammenfassung'},
 ]
 </script>
 
@@ -93,14 +96,20 @@ const steps = [
                 <StepArrival        v-if="currentStep === 4" :formData="formData" :event="event" @next="goToStep" @back="goToStep" />
                 <StepRegistrationMode v-if="currentStep === 5" :formData="formData" :event="event" @next="goToStep" @back="goToStep" />
                 <StepAddons         v-if="currentStep === 6" :formData="formData" :event="event" :selectedAddons="selectedAddons" @next="goToStep" @back="goToStep" />
-                <StepPhotoPermissions v-if="currentStep === 7" :formData="formData" :event="event" @next="goToStep" @back="goToStep" />
+                <StepParticipationOptions v-if="currentStep === 7" :formData="formData" :event="event" @next="goToStep"
-                <StepAllergies      v-if="currentStep === 8" :formData="formData" :event="event" @next="goToStep" @back="goToStep" />
+                                          @back="goToStep"/>
-                <StepPaymentMethod v-if="currentStep === 9" :formData="formData" :event="event" @next="goToStep"
+                <StepPhotoPermissions v-if="currentStep === 8" :formData="formData" :event="event" @next="goToStep"
+                                      @back="goToStep"/>
+                <StepAllergies v-if="currentStep === 9" :formData="formData" :event="event" @next="goToStep"
+                               @back="goToStep"/>
+                <StepPaymentMethod v-if="currentStep === 10" :formData="formData" :event="event" @next="goToStep"
                                    @back="goToStep"/>
                 <StepSummary
-                    v-if="currentStep === 10"
+                    v-if="currentStep === 11"
                     :formData="formData"
                     :event="event"
+                    :summaryBaseAmount="summaryBaseAmount"
+                    :summaryAddonLines="summaryAddonLines"
                     :summaryAmount="summaryAmount"
                     :summaryAmountValue="summaryAmountValue"
                     :summaryLoading="summaryLoading"

app/Domains/Event/Views/Partials/SignUpForm/composables/stepFlow.js

@@ -0,0 +1,45 @@
+// Zentrale Schrittreihenfolge des Anmelde-Wizards. Einige Schritte sind optional und werden
+// übersprungen, wenn sie für das Event nicht zutreffen (Zusatzoptionen, Teilnahmeoptionen).
+// Der Zahlungsschritt wird separat in useSignupForm anhand des berechneten Betrags übersprungen.
+export const STEP_AGE = 1
+export const STEP_CONTACT = 2
+export const STEP_PERSONAL = 3
+export const STEP_ARRIVAL = 4
+export const STEP_REGISTRATION = 5
+export const STEP_ADDONS = 6
+export const STEP_PARTICIPATION_OPTIONS = 7
+export const STEP_PHOTO = 8
+export const STEP_ALLERGIES = 9
+export const STEP_PAYMENT = 10
+export const STEP_SUMMARY = 11
+
+// Ob ein (optionaler) Schritt für dieses Event angezeigt wird.
+export function stepVisible(event, step) {
+    if (step === STEP_ADDONS) {
+        return (event.addons?.length ?? 0) > 0
+    }
+
+    if (step === STEP_PARTICIPATION_OPTIONS) {
+        return (event.participationOptions?.length ?? 0) > 0
+    }
+
+    return true
+}
+
+// Nächster sichtbarer Schritt nach `step` (überspringt ausgeblendete optionale Schritte).
+export function nextVisibleFrom(event, step) {
+    let candidate = step + 1
+    while (candidate < STEP_SUMMARY && !stepVisible(event, candidate)) {
+        candidate++
+    }
+    return candidate
+}
+
+// Vorheriger sichtbarer Schritt vor `step`.
+export function prevVisibleFrom(event, step) {
+    let candidate = step - 1
+    while (candidate > STEP_AGE && !stepVisible(event, candidate)) {
+        candidate--
+    }
+    return candidate
+}

app/Domains/Event/Views/Partials/SignUpForm/composables/useSignupForm.js

@@ -1,5 +1,6 @@
 import {reactive, ref} from 'vue'
 import axios from 'axios'
+import {STEP_PAYMENT, STEP_SUMMARY} from './stepFlow.js'
 
 export function useSignupForm(event, participantData) {
     const currentStep = ref(1)
@@ -16,6 +17,8 @@ export function useSignupForm(event, participantData) {
         eatingHabit: 'EATING_HABIT_VEGAN',
         paymentMethod: activeMethods.length === 1 ? activeMethods[0].slug : null,
         paymentOptions: {},
+        // Antworten auf die event-spezifischen Teilnahmeoptionen: { [question.key]: option.value }
+        participationOptions: {},
         userId: participantData.id,
         eventId: event.id,
         vorname: participantData.firstname ?? '',
@@ -57,6 +60,8 @@ export function useSignupForm(event, participantData) {
 
     const summaryAmount = ref('')
     const summaryAmountValue = ref(0)
+    const summaryBaseAmount = ref('')
+    const summaryAddonLines = ref([])
 
     const fetchAmount = async () => {
         summaryLoading.value = true
@@ -74,15 +79,13 @@ export function useSignupForm(event, participantData) {
             })
             summaryAmount.value = res.data.amount
             summaryAmountValue.value = Number(res.data.amountValue ?? 0)
+            summaryBaseAmount.value = res.data.baseAmount ?? ''
+            summaryAddonLines.value = res.data.addons ?? []
         } finally {
             summaryLoading.value = false
         }
     }
 
-    // Steps: ... 8 Allergien, 9 Zahlungsart, 10 Zusammenfassung.
-    const STEP_PAYMENT = 9
-    const STEP_SUMMARY = 10
-
     const goToStep = async (step) => {
         if (step === STEP_PAYMENT) {
             // Betrag ermitteln: Bei 0 € wird die Zahlungsart-Auswahl übersprungen.
@@ -129,6 +132,8 @@ export function useSignupForm(event, participantData) {
         submitResult,
         summaryLoading,
         summaryAmount,
-        summaryAmountValue
+        summaryAmountValue,
+        summaryBaseAmount,
+        summaryAddonLines
     }
 }

app/Domains/Event/Views/Partials/SignUpForm/steps/StepAddons.vue

@@ -1,6 +1,10 @@
 <script setup>
+import {nextVisibleFrom, STEP_ADDONS} from "../composables/stepFlow.js";
+
 const props = defineProps({ formData: Object, event: Object, selectedAddons: Object })
 const emit = defineEmits(['next', 'back'])
+
+const next = () => emit('next', nextVisibleFrom(props.event, STEP_ADDONS))
 </script>
 
 <template>
@@ -25,13 +29,21 @@ const emit = defineEmits(['next', 'back'])
         <!-- Addons -->
         <div v-if="event.addons?.length > 0">
             <h3>Zusatzoptionen</h3>
-            <div v-for="addon in event.addons" :key="addon.id" style="margin-bottom: 16px; padding: 12px; background: #f8fafc; border-radius: 8px;">
+            <div v-for="addon in event.addons" :key="addon.key"
+                 style="margin-bottom: 16px; padding: 12px; background: #f8fafc; border-radius: 8px;">
                 <label style="display: flex; gap: 12px; cursor: pointer;">
-                    <input type="checkbox" v-model="selectedAddons[addon.id]" style="margin-top: 4px;" />
+                    <input type="checkbox" v-model="selectedAddons[addon.key]" style="margin-top: 4px;"/>
                     <span>
-                        <strong>{{ addon.name }}</strong>
+                        <strong>{{ addon.title }}</strong>
-                        <span style="display: block; color: #6b7280; font-size: 0.875rem;">Betrag: {{ addon.amount }}</span>
+                        <span style="display: block; color: #6b7280; font-size: 0.875rem;">
-                        <span style="display: block; color: #374151; font-size: 0.875rem; margin-top: 4px;">{{ addon.description }}</span>
+                            <template v-if="addon.free">Kostenfrei</template>
+                            <template v-else>{{ addon.priceReadable }}<template
+                                v-if="!addon.flat"> / Tag</template></template>
+                        </span>
+                        <span v-if="addon.description"
+                              style="display: block; color: #374151; font-size: 0.875rem; margin-top: 4px;">{{
+                                addon.description
+                            }}</span>
                     </span>
                 </label>
             </div>
@@ -39,7 +51,7 @@ const emit = defineEmits(['next', 'back'])
 
         <div class="btn-row">
             <button type="button" class="btn-secondary" @click="emit('back', 5)">← Zurück</button>
-            <button type="button" class="btn-primary" @click="emit('next', 7)">Weiter →</button>
+            <button type="button" class="btn-primary" @click="next">Weiter →</button>
         </div>
     </div>
 </template>

app/Domains/Event/Views/Partials/SignUpForm/steps/StepAllergies.vue

@@ -43,8 +43,8 @@ const emit = defineEmits(['next', 'back'])
             </tr>
             <tr>
                 <td colspan="2" class="btn-row">
-                    <button type="button" class="btn-secondary" @click="emit('back', 7)">← Zurück</button>
+                    <button type="button" class="btn-secondary" @click="emit('back', 8)">← Zurück</button>
-                    <button type="button" class="btn-primary" @click="emit('next', 9)">Weiter →</button>
+                    <button type="button" class="btn-primary" @click="emit('next', 10)">Weiter →</button>
                 </td>
             </tr>
         </table>

app/Domains/Event/Views/Partials/SignUpForm/steps/StepParticipationOptions.vue

@@ -0,0 +1,62 @@
+<script setup>
+import {computed} from "vue";
+import {nextVisibleFrom, prevVisibleFrom, STEP_PARTICIPATION_OPTIONS} from "../composables/stepFlow.js";
+
+const props = defineProps({formData: Object, event: Object})
+const emit = defineEmits(['next', 'back'])
+
+const questions = computed(() => props.event.participationOptions ?? [])
+
+// Pflichtfeld: "Weiter" erst möglich, wenn jede Frage beantwortet ist.
+const canProceed = computed(() =>
+    questions.value.every(q => {
+        const value = props.formData.participationOptions[q.key]
+        return value !== undefined && value !== null && String(value).trim() !== ''
+    })
+)
+
+const back = () => emit('back', prevVisibleFrom(props.event, STEP_PARTICIPATION_OPTIONS))
+const next = () => emit('next', nextVisibleFrom(props.event, STEP_PARTICIPATION_OPTIONS))
+</script>
+
+<template>
+    <div>
+        <h3>Teilnahmeoptionen</h3>
+        <p style="color: #6b7280; font-size: 0.95rem; margin-bottom: 20px;">
+            Bitte triff für jede Auswahl eine Entscheidung.
+        </p>
+
+        <table class="form-table">
+            <tr v-for="question in questions" :key="question.key">
+                <td>
+                    {{ question.title || question.label }}:
+                    <span v-if="question.title && question.label" class="option-hint">{{ question.label }}</span>
+                </td>
+                <td>
+                    <select v-model="formData.participationOptions[question.key]">
+                        <option value="">Bitte wählen</option>
+                        <option v-for="option in question.options" :key="option.value" :value="option.value">
+                            {{ option.label }}
+                        </option>
+                    </select>
+                </td>
+            </tr>
+        </table>
+
+        <div class="btn-row">
+            <button type="button" class="btn-secondary" @click="back">← Zurück</button>
+            <button type="button" class="btn-primary" :disabled="!canProceed" @click="next">Weiter →</button>
+        </div>
+    </div>
+</template>
+
+<style scoped>
+.option-hint {
+    display: block;
+    margin-top: 2px;
+    font-size: 0.8rem;
+    font-style: italic;
+    font-weight: 400;
+    color: #6b7280;
+}
+</style>

app/Domains/Event/Views/Partials/SignUpForm/steps/StepPaymentMethod.vue

@@ -78,8 +78,8 @@ const canProceed = computed(() => {
         </div>
 
         <div class="btn-row">
-            <button type="button" class="btn-secondary" @click="emit('back', 8)">← Zurück</button>
+            <button type="button" class="btn-secondary" @click="emit('back', 9)">← Zurück</button>
-            <button type="button" class="btn-primary" :disabled="!canProceed" @click="emit('next', 10)">Weiter →
+            <button type="button" class="btn-primary" :disabled="!canProceed" @click="emit('next', 11)">Weiter →
             </button>
         </div>
     </div>

app/Domains/Event/Views/Partials/SignUpForm/steps/StepPhotoPermissions.vue

@@ -1,16 +1,15 @@
 <script setup>
+import {prevVisibleFrom, STEP_ALLERGIES, STEP_PHOTO} from "../composables/stepFlow.js";
+
 const props = defineProps({ formData: Object, event: Object })
 const emit = defineEmits(['next', 'back'])
 
 const acceptAll = () => {
     Object.keys(props.formData.foto).forEach(k => props.formData.foto[k] = true)
-    emit('next', 8)
+    emit('next', STEP_ALLERGIES)
 }
 
-const back = () => {
+const back = () => emit('back', prevVisibleFrom(props.event, STEP_PHOTO))
-    const hasAddons = (props.event.addons?.length > 0) || props.event.solidarityPayment
-    emit('back', hasAddons ? 6 : 5)
-}
 </script>
 
 <template>
@@ -27,7 +26,7 @@ const back = () => {
         <div class="btn-row">
             <button type="button" class="btn-secondary" @click="back">← Zurück</button>
             <button type="button" class="btn-primary" style="background: #059669;" @click="acceptAll">Alle akzeptieren & weiter</button>
-            <button type="button" class="btn-primary" @click="emit('next', 8)">Weiter →</button>
+            <button type="button" class="btn-primary" @click="emit('next', 9)">Weiter →</button>
         </div>
     </div>
 </template>

app/Domains/Event/Views/Partials/SignUpForm/steps/StepRegistrationMode.vue

@@ -1,5 +1,6 @@
 <script setup>
 import {watch} from "vue";
+import {nextVisibleFrom, STEP_REGISTRATION} from "../composables/stepFlow.js";
 
 const props = defineProps({ formData: Object, event: Object })
 const emit = defineEmits(['next', 'back'])
@@ -17,8 +18,7 @@ watch(
 )
 
 const nextStep = () => {
-    const hasAddons = (props.event.addons?.length ?? 0) > 0
+    emit('next', nextVisibleFrom(props.event, STEP_REGISTRATION))
-    emit('next', hasAddons ? 6 : 7)
 }
 </script>
 

app/Domains/Event/Views/Partials/SignUpForm/steps/StepSummary.vue

@@ -7,6 +7,8 @@ const PAYMENT_ACCOUNT_TRANSACTION = 'PAYMENT_ACCOUNT_TRANSACTION'
 const props = defineProps({
     formData: Object,
     event: Object,
+    summaryBaseAmount: {type: String, default: ''},
+    summaryAddonLines: {type: Array, default: () => []},
     summaryAmount: String,
     summaryAmountValue: {type: Number, default: 0},
     summaryLoading: Boolean,
@@ -32,8 +34,17 @@ const paymentConfirmationText = computed(() => {
     return template.replaceAll('{amount}', props.summaryAmount ?? '')
 })
 
-// Zurück führt zur Zahlungsart (9), sofern dieser Schritt gezeigt wurde; bei 0 € direkt zu Allergien (8).
+// Zurück führt zur Zahlungsart (10), sofern dieser Schritt gezeigt wurde; bei 0 € direkt zu Allergien (9).
-const backTarget = computed(() => props.summaryAmountValue > 0 ? 9 : 8)
+const backTarget = computed(() => props.summaryAmountValue > 0 ? 10 : 9)
+
+// Gewählte Teilnahmeoptionen für die Zusammenfassung (label statt value anzeigen).
+const selectedParticipationOptions = computed(() =>
+    (props.event.participationOptions ?? []).map(question => {
+        const value = props.formData.participationOptions[question.key]
+        const option = (question.options ?? []).find(o => o.value === value)
+        return {label: question.title || question.label, value: option?.label ?? ''}
+    }).filter(entry => entry.value !== '')
+)
 
 const canSubmit = computed(() =>
     props.formData.summary_information_correct
@@ -115,6 +126,11 @@ function eatingHabit() {
                     <td>{{ participationGroup() }}</td>
                 </tr>
 
+                <tr v-for="option in selectedParticipationOptions" :key="option.label">
+                    <td>{{ option.label }}:</td>
+                    <td>{{ option.value }}</td>
+                </tr>
+
                 <tr>
                     <td>Foto-Erlaubnis:</td>
                     <td>
@@ -149,6 +165,22 @@ function eatingHabit() {
                 <tr><td>Abreise:</td><td>{{ formatDate(formData.departure) }}</td></tr>
             </table>
 
+            <h4 style="margin: 0 0 8px 0;">Kostenübersicht</h4>
+            <table class="form-table cost-table" style="margin-bottom: 20px;">
+                <tr>
+                    <td>Teilnahmebeitrag:</td>
+                    <td>{{ summaryBaseAmount }}</td>
+                </tr>
+                <tr v-for="addon in summaryAddonLines" :key="addon.key">
+                    <td>{{ addon.title }}:</td>
+                    <td>{{ addon.free ? 'Kostenfrei' : addon.amount }}</td>
+                </tr>
+                <tr class="cost-total">
+                    <td><strong>Gesamtbetrag:</strong></td>
+                    <td><strong>{{ summaryAmount }}</strong></td>
+                </tr>
+            </table>
+
             <div style="display: flex; flex-direction: column; gap: 10px; margin-bottom: 20px;">
                 <label style="display: flex; gap: 10px; cursor: pointer;">
                     <input type="checkbox" v-model="formData.summary_information_correct" />
@@ -182,3 +214,10 @@ function eatingHabit() {
         </div>
     </div>
 </template>
+
+<style scoped>
+.cost-table .cost-total td {
+    border-top: 1px solid #d1d5db;
+    padding-top: 8px;
+}
+</style>

app/Enumerations/TaxExemptionReason.php

@@ -0,0 +1,70 @@
+<?php
+
+namespace App\Enumerations;
+
+use App\Scopes\CommonModel;
+
+/**
+ * Gründe für eine Umsatzsteuerbefreiung -- DB-gestützt (analog {@see PaymentStatus}), damit Label und
+ * der auf der Rechnung verpflichtende Hinweis nach § 14 Abs. 4 Nr. 8 UStG zentral pflegbar sind.
+ * Gemeinnützigkeit allein befreit nicht; die Befreiung braucht immer einen konkreten Rechtsgrund
+ * (Vereins-Fälle über § 4 Nr. 22a / Nr. 25).
+ *
+ * @property string $slug
+ * @property string $name
+ * @property string $invoice_text
+ * @property bool $requires_note
+ * @property int $sort_order
+ */
+class TaxExemptionReason extends CommonModel
+{
+    public const string USTG_19 = 'ustg_19';
+    public const string USTG_4_24 = 'ustg_4_24';
+    public const string USTG_4_25A = 'ustg_4_25a';
+    public const string USTG_4_22A = 'ustg_4_22a';
+    public const string CUSTOM = 'custom';
+
+    protected $table = 'tax_exemption_reasons';
+    protected $primaryKey = 'slug';
+    public $incrementing = false;
+    protected $keyType = 'string';
+
+    protected $fillable = [
+        'slug',
+        'name',
+        'invoice_text',
+        'requires_note',
+        'sort_order',
+    ];
+
+    protected $casts = [
+        'requires_note' => 'boolean',
+        'sort_order' => 'integer',
+    ];
+
+    /**
+     * Pflichthinweis für die Rechnung. Bei einem individuellen Grund (requires_note) wird der hinterlegte
+     * Freitext des Tenants verwendet.
+     */
+    public function invoiceText(?string $customNote = null): string
+    {
+        return $this->requires_note ? trim((string) $customNote) : $this->invoice_text;
+    }
+
+    /**
+     * Optionen für das Frontend inkl. Vorschau-Text. Bei einem Freitext-Grund ist `text` leer, da der Text
+     * erst aus dem Freitext des Tenants entsteht.
+     *
+     * @return array<int, array{value: string, label: string, text: string}>
+     */
+    public static function options(): array
+    {
+        return self::orderBy('sort_order')->get()
+            ->map(static fn (self $reason): array => [
+                'value' => $reason->slug,
+                'label' => $reason->name,
+                'text' => $reason->requires_note ? '' : $reason->invoice_text,
+            ])
+            ->all();
+    }
+}

app/Enumerations/VatPricingMode.php

@@ -0,0 +1,38 @@
+<?php
+
+namespace App\Enumerations;
+
+/**
+ * Preismodus bei bestehender Umsatzsteuerpflicht: entweder ist die USt bereits im konfigurierten Beitrag
+ * enthalten (Brutto/„Supermarkt") oder sie wird bei der Preisermittlung aufgeschlagen (Netto). Gespeichert
+ * wird immer der finale Brutto-Beitrag; der Modus beeinflusst nur die Preisermittlung im Anmeldeprozess.
+ */
+enum VatPricingMode: string
+{
+    case Inclusive = 'inclusive';
+    case AddOn = 'add_on';
+
+    public function label(): string
+    {
+        return match ($this) {
+            self::Inclusive => 'Inklusive – Beiträge sind Endpreise (USt enthalten)',
+            self::AddOn => 'Aufschlagen – USt wird auf die Beiträge aufgeschlagen',
+        };
+    }
+
+    /**
+     * Optionen für das Frontend: [['value' => ..., 'label' => ...], ...].
+     *
+     * @return array<int, array{value: string, label: string}>
+     */
+    public static function options(): array
+    {
+        return array_map(
+            static fn (self $mode): array => [
+                'value' => $mode->value,
+                'label' => $mode->label(),
+            ],
+            self::cases(),
+        );
+    }
+}

app/Mail/AdminMails/CostUnitInvalidBillingDeadlineMail.php

@@ -0,0 +1,55 @@
+<?php
+
+namespace App\Mail\AdminMails;
+
+use Illuminate\Mail\Mailable;
+use Illuminate\Mail\Mailables\Attachment;
+use Illuminate\Mail\Mailables\Content;
+use Illuminate\Mail\Mailables\Envelope;
+
+class CostUnitInvalidBillingDeadlineMail extends Mailable
+{
+    public function __construct(
+        private int|string $costUnitId,
+        private ?string    $costUnitName,
+        private ?string    $invalidBillingDeadline,
+    )
+    {
+        //
+    }
+
+    /**
+     * Get the message envelope.
+     */
+    public function envelope(): Envelope
+    {
+        return new Envelope(
+            subject: sprintf('Ungültiges Abrechnungsende für Kostenstelle #%s', $this->costUnitId),
+        );
+    }
+
+    /**
+     * Get the message content definition.
+     */
+    public function content(): Content
+    {
+        return new Content(
+            view: 'emails.admin.cost_unit_invalid_billing_deadline',
+            with: [
+                'costUnitId' => $this->costUnitId,
+                'costUnitName' => $this->costUnitName,
+                'invalidBillingDeadline' => $this->invalidBillingDeadline,
+            ],
+        );
+    }
+
+    /**
+     * Get the attachments for the message.
+     *
+     * @return array<int, Attachment>
+     */
+    public function attachments(): array
+    {
+        return [];
+    }
+}

app/Models/Event.php

@@ -8,14 +8,11 @@ use App\Enumerations\EatingHabit;
 use App\Enumerations\ParticipationFeeType;
 use App\RelationModels\EventParticipationFee;
 use App\RelationModels\EventPaymentMethods;
-use App\Resources\EventResource;
-use App\Scopes\CommonModel;
 use App\Scopes\InstancedModel;
 use DateTime;
 use Illuminate\Database\Eloquent\Relations\BelongsTo;
 use Illuminate\Database\Eloquent\Relations\BelongsToMany;
 use Illuminate\Database\Eloquent\Relations\HasMany;
-use Illuminate\Http\Resources\Json\JsonResource;
 
 /**
  * @property string $tenant
@@ -85,6 +82,13 @@ class Event extends InstancedModel
         'support_flat',
         'alcoholics_age',
         'archived',
+        'tax_liable',
+        'vat_rate',
+        'vat_pricing_mode',
+        'tax_exemption_reason',
+        'tax_exemption_note',
+        'participation_options',
+        'addons',
 
     ];
 
@@ -109,6 +113,12 @@ class Event extends InstancedModel
         'total_max_amount' => AmountCast::class,
 
         'sibling_reduction' => 'boolean',
+
+        'tax_liable' => 'boolean',
+        'vat_rate' => 'integer',
+
+        'participation_options' => 'array',
+        'addons' => 'array',
     ];
 
     public function tenant(): BelongsTo

app/Models/EventParticipant.php

@@ -14,6 +14,7 @@ use App\EventPaymentModules\DTO\RegistrationSummaryResponse;
 use App\EventPaymentModules\EventPaymentModule;
 use App\EventPaymentModules\EventPaymentModuleRegistry;
 use App\Scopes\InstancedModel;
+use Illuminate\Database\Eloquent\Relations\HasMany;
 
 
 class EventParticipant extends InstancedModel
@@ -103,6 +104,18 @@ class EventParticipant extends InstancedModel
         return $this->belongsTo(Event::class);
     }
 
+    /** Gewählte Teilnahmeoptionen (event-spezifische Pflicht-Auswahl) dieser Anmeldung. */
+    public function selectedOptions(): HasMany
+    {
+        return $this->hasMany(EventParticipantOption::class, 'event_participant_id');
+    }
+
+    /** Gebuchte Zusätze (Event-Addons) dieser Anmeldung. */
+    public function selectedAddons(): HasMany
+    {
+        return $this->hasMany(EventParticipantAddon::class, 'event_participant_id');
+    }
+
     public function user()
     {
         return $this->belongsTo(User::class);

app/Models/EventParticipantAddon.php

@@ -0,0 +1,41 @@
+<?php
+
+namespace App\Models;
+
+use App\Casts\AmountCast;
+use App\Scopes\InstancedModel;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class EventParticipantAddon extends InstancedModel
+{
+    protected $table = 'event_participant_addons';
+
+    protected $fillable = [
+        'tenant',
+        'event_id',
+        'event_participant_id',
+        'addon_key',
+        'title',
+        'price',
+        'flat',
+        'days',
+        'amount',
+    ];
+
+    protected $casts = [
+        'flat' => 'boolean',
+        'days' => 'integer',
+        'price' => AmountCast::class,
+        'amount' => AmountCast::class,
+    ];
+
+    public function event(): BelongsTo
+    {
+        return $this->belongsTo(Event::class);
+    }
+
+    public function participant(): BelongsTo
+    {
+        return $this->belongsTo(EventParticipant::class, 'event_participant_id');
+    }
+}

app/Models/EventParticipantOption.php

@@ -0,0 +1,31 @@
+<?php
+
+namespace App\Models;
+
+use App\Scopes\InstancedModel;
+use Illuminate\Database\Eloquent\Relations\BelongsTo;
+
+class EventParticipantOption extends InstancedModel
+{
+    protected $table = 'event_participant_options';
+
+    protected $fillable = [
+        'tenant',
+        'event_id',
+        'event_participant_id',
+        'question_key',
+        'question_label',
+        'value',
+        'value_label',
+    ];
+
+    public function event(): BelongsTo
+    {
+        return $this->belongsTo(Event::class);
+    }
+
+    public function participant(): BelongsTo
+    {
+        return $this->belongsTo(EventParticipant::class, 'event_participant_id');
+    }
+}

app/Models/Tenant.php

@@ -21,6 +21,11 @@ use App\Scopes\CommonModel;
  * @property string $url_participation_rules
  * @property boolean $events_allowed
  * @property boolean $has_active_instance
+ * @property boolean $tax_liable
+ * @property int $vat_rate
+ * @property string|null $tax_exemption_reason
+ * @property string|null $tax_exemption_note
+ * @property string $vat_pricing_mode
  */
 class Tenant extends CommonModel
 {
@@ -46,6 +51,16 @@ class Tenant extends CommonModel
         'impress_text',
         'url_participation_rules',
         'is_active_local_group',
-        'has_active_instance'
+        'has_active_instance',
+        'tax_liable',
+        'vat_rate',
+        'tax_exemption_reason',
+        'tax_exemption_note',
+        'vat_pricing_mode',
+    ];
+
+    protected $casts = [
+        'tax_liable' => 'boolean',
+        'vat_rate' => 'integer',
     ];
 }

app/Repositories/EventParticipantRepository.php

@@ -63,6 +63,122 @@ class EventParticipantRepository {
         return $participants;
     }
 
+    /**
+     * Gruppiert die (aktiven) Teilnehmenden nach ihren gewählten Teilnahmeoptionen. Je am Event definierter
+     * Frage entsteht eine Sektion mit Gruppen „Frage: Option" (in Definition-Reihenfolge); Teilnehmende ohne
+     * Antwort landen unter „Frage: (keine Angabe)". Ein Teilnehmer erscheint je Frage einmal, kann also über
+     * mehrere Fragen hinweg in mehreren Gruppen auftauchen. `$filter` liefert nur die eine passende Gruppe
+     * (für die E-Mail-Auflösung in ByGroupController).
+     */
+    public function groupByParticipationOption(Event $event, Request $request, ?string $filter = null): array
+    {
+        $definitions = $event->participation_options ?? [];
+        $allParticipants = $this->getForList($event, $request);
+        $groups = [];
+
+        foreach ($definitions as $question) {
+            $questionKey = $question['key'] ?? null;
+            if ($questionKey === null) {
+                continue;
+            }
+
+            // Überschrift: bevorzugt der Titel, sonst die (längere) Frage bzw. der Key als Fallback.
+            $questionLabel = trim((string)($question['title'] ?? '')) !== ''
+                ? $question['title']
+                : ($question['label'] ?? $questionKey);
+            $noAnswerKey = $questionLabel . ': (keine Angabe)';
+
+            // Vordefinierte Optionen in Reihenfolge: value => Gruppen-Key.
+            $definedGroupKeys = [];
+            foreach ($question['options'] ?? [] as $option) {
+                $definedGroupKeys[$option['value']] = $questionLabel . ': ' . ($option['label'] ?? $option['value']);
+            }
+
+            $collected = [];
+            foreach ($allParticipants as $participant) {
+                $answer = null;
+                foreach ($participant['participationOptions'] ?? [] as $selectedOption) {
+                    if (($selectedOption['questionKey'] ?? null) === $questionKey) {
+                        $answer = $selectedOption;
+                        break;
+                    }
+                }
+
+                if ($answer === null || ($answer['value'] ?? '') === '') {
+                    $collected[$noAnswerKey][] = $participant;
+                    continue;
+                }
+
+                // Bevorzugt die definierte Option; falls sie zwischenzeitlich entfernt wurde, den Snapshot nutzen.
+                $groupKey = $definedGroupKeys[$answer['value']] ?? ($questionLabel . ': ' . ($answer['valueLabel'] ?? $answer['value']));
+                $collected[$groupKey][] = $participant;
+            }
+
+            // Ausgabe je Frage: definierte Optionen zuerst (in Reihenfolge), dann Snapshot-Reste, „(keine Angabe)" ans Ende.
+            foreach ($definedGroupKeys as $groupKey) {
+                if (!empty($collected[$groupKey])) {
+                    $groups[$groupKey] = $collected[$groupKey];
+                    unset($collected[$groupKey]);
+                }
+            }
+
+            foreach ($collected as $groupKey => $participants) {
+                if ($groupKey === $noAnswerKey) {
+                    continue;
+                }
+                $groups[$groupKey] = $participants;
+            }
+
+            if (!empty($collected[$noAnswerKey])) {
+                $groups[$noAnswerKey] = $collected[$noAnswerKey];
+            }
+        }
+
+        if ($filter !== null) {
+            return array_key_exists($filter, $groups) ? [$filter => $groups[$filter]] : [];
+        }
+
+        return $groups;
+    }
+
+    /**
+     * Gruppiert die (aktiven) Teilnehmenden nach ihren gebuchten Zusätzen (Event-Addons). Da Addons Ja/Nein
+     * sind, entsteht eine Gruppe je Zusatz (Überschrift = Addon-Titel) mit den Teilnehmenden, die ihn gebucht
+     * haben; ein Teilnehmer kann in mehreren Gruppen auftauchen. Nur nicht-leere Gruppen. Die Reihenfolge folgt
+     * der Event-Definition; nachträglich entfernte Addons werden über den Snapshot-Titel weiterhin abgedeckt.
+     */
+    public function groupByAddon(Event $event, Request $request, ?string $filter = null): array
+    {
+        $allParticipants = $this->getForList($event, $request);
+
+        // Gruppen-Reihenfolge aus der Event-Definition vorbelegen (leere Gruppen werden am Ende verworfen).
+        $groups = [];
+        foreach ($event->addons ?? [] as $addon) {
+            $title = $addon['title'] ?? ($addon['key'] ?? null);
+            if ($title !== null) {
+                $groups[$title] = [];
+            }
+        }
+
+        foreach ($allParticipants as $participant) {
+            foreach ($participant['selectedAddons'] ?? [] as $selectedAddon) {
+                $title = $selectedAddon['title'] ?? ($selectedAddon['addonKey'] ?? null);
+                if ($title === null) {
+                    continue;
+                }
+                $groups[$title][] = $participant;
+            }
+        }
+
+        $groups = array_filter($groups, fn($group) => count($group) > 0);
+
+        if ($filter !== null) {
+            return array_key_exists($filter, $groups) ? [$filter => $groups[$filter]] : [];
+        }
+
+        return $groups;
+    }
+
     public function getSignedOffParticipants(Event $event, Request $request, ?string $filter = null) : array {
         $allParticipants = $this->getForList($event, $request, true);
         $participants = [];

app/Resources/EventParticipantAddonResource.php

@@ -0,0 +1,26 @@
+<?php
+
+namespace App\Resources;
+
+use App\Models\EventParticipantAddon;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class EventParticipantAddonResource extends JsonResource
+{
+    function __construct(EventParticipantAddon $addon)
+    {
+        parent::__construct($addon);
+    }
+
+    public function toArray($request): array
+    {
+        return [
+            'addonKey' => $this->resource->addon_key,
+            'title' => $this->resource->title,
+            'flat' => $this->resource->flat,
+            'amount' => $this->resource->amount?->getAmount() ?? 0,
+            'amountReadable' => $this->resource->amount?->toString() ?? '0,00 Euro',
+            'free' => ($this->resource->amount?->getAmount() ?? 0) <= 0,
+        ];
+    }
+}

app/Resources/EventParticipantOptionResource.php

@@ -0,0 +1,24 @@
+<?php
+
+namespace App\Resources;
+
+use App\Models\EventParticipantOption;
+use Illuminate\Http\Resources\Json\JsonResource;
+
+class EventParticipantOptionResource extends JsonResource
+{
+    function __construct(EventParticipantOption $option)
+    {
+        parent::__construct($option);
+    }
+
+    public function toArray($request): array
+    {
+        return [
+            'questionKey' => $this->resource->question_key,
+            'questionLabel' => $this->resource->question_label,
+            'value' => $this->resource->value,
+            'valueLabel' => $this->resource->value_label,
+        ];
+    }
+}

app/Resources/EventParticipantResource.php

@@ -96,6 +96,10 @@ class EventParticipantResource extends JsonResource
                 'eventName' => $this->resource->event()->first()->name,
                 'arrivalDateReadable' => $this->resource->arrival_date->format('d.m.Y'),
                 'departureDateReadable' => $this->resource->departure_date->format('d.m.Y'),
+                'participationOptions' => $this->resource->selectedOptions()->get()->map(
+                    fn($option) => new EventParticipantOptionResource($option)->toArray($request))->toArray(),
+                'selectedAddons' => $this->resource->selectedAddons()->get()->map(
+                    fn($addon) => new EventParticipantAddonResource($addon)->toArray($request))->toArray(),
             ]
         );
     }

app/Resources/EventResource.php

@@ -4,6 +4,7 @@ namespace App\Resources;
 
 use App\Enumerations\ParticipationFeeType;
 use App\Enumerations\ParticipationType;
+use App\Enumerations\VatPricingMode;
 use App\Models\Event;
 use App\ValueObjects\Amount;
 use DateTime;
@@ -137,6 +138,23 @@ class EventResource extends JsonResource{
         $returnArray['paymentMethods'] = $this->event->paymentMethods()->get()->map(
             fn($paymentMethod) => new AvailablePaymentMethodResource($paymentMethod)->toArray($request))->toArray();
 
+        // Veranstaltungsspezifische Pflicht-Auswahlfragen (Teilnahmeoptionen); leeres Array => Schritt entfällt.
+        $returnArray['participationOptions'] = $this->event->participation_options ?? [];
+
+        // Buchbare Zusätze (Event-Addons); leeres Array => Schritt entfällt. Preis 0 => "Kostenfrei".
+        $returnArray['addons'] = collect($this->event->addons ?? [])->map(function ($addon) {
+            $price = (float)($addon['price'] ?? 0);
+            return [
+                'key' => $addon['key'] ?? '',
+                'title' => $addon['title'] ?? '',
+                'description' => $addon['description'] ?? '',
+                'price' => $price,
+                'priceReadable' => new Amount($price, 'Euro')->toString(),
+                'free' => $price <= 0,
+                'flat' => (bool)($addon['flat'] ?? false),
+            ];
+        })->toArray();
+
 
         $returnArray['participationTypes'] = [];
 
@@ -342,7 +360,61 @@ class EventResource extends JsonResource{
             $basicFee = $basicFee->multiply(0.5);
         }
 
-        return $basicFee;
+        // Bei bestehender USt-Pflicht und Netto-Preismodus die USt aufschlagen; gespeichert wird immer der
+        // finale Brutto-Betrag. Bei "inklusive" oder ohne Steuerpflicht bleibt der Beitrag unverändert.
+        if ($this->event->tax_liable && $this->event->vat_pricing_mode === VatPricingMode::AddOn->value) {
+            $basicFee = $basicFee->multiply(1 + $this->event->vat_rate / 100);
+        }
+
+        return new Amount(round($basicFee->getAmount(), 2), 'Euro');
+    }
+
+    /**
+     * Löst die gewählten Zusätze (Event-Addons) gegen die Event-Definition auf und berechnet je Position den
+     * Betrag: Pauschale => Preis, sonst Preis × Teilnahmetage. Bei USt-Pflicht + Netto-Preismodus (`add_on`)
+     * wird die USt aufgeschlagen (analog Beitrag); bei „inclusive"/keiner Pflicht bleibt der Preis unverändert.
+     * Kein Early-Bird-Aufschlag.
+     *
+     * @param array<int, string> $selectedKeys
+     * @return array{items: array<int, array{key: string, title: string, price: float, flat: bool, days: int, amount: float}>, total: Amount}
+     */
+    public function resolveAddons(array $selectedKeys, DateTime $arrival, DateTime $departure): array
+    {
+        $days = $arrival->diff($departure)->days + 1;
+        $addsVat = $this->event->tax_liable && $this->event->vat_pricing_mode === VatPricingMode::AddOn->value;
+
+        $items = [];
+        $total = new Amount(0, 'Euro');
+
+        foreach ($this->event->addons ?? [] as $addon) {
+            $key = $addon['key'] ?? null;
+            if ($key === null || !in_array($key, $selectedKeys, true)) {
+                continue;
+            }
+
+            $price = (float)($addon['price'] ?? 0);
+            $flat = (bool)($addon['flat'] ?? false);
+            $usedDays = $flat ? 1 : $days;
+
+            $amount = $flat ? $price : $price * $days;
+            if ($addsVat) {
+                $amount *= 1 + $this->event->vat_rate / 100;
+            }
+            $amount = round($amount, 2);
+
+            $items[] = [
+                'key' => $key,
+                'title' => $addon['title'] ?? $key,
+                'price' => $price,
+                'flat' => $flat,
+                'days' => $usedDays,
+                'amount' => $amount,
+            ];
+
+            $total->addAmount(new Amount($amount, 'Euro'));
+        }
+
+        return ['items' => $items, 'total' => $total];
     }
 }
 

app/Tasks/CloseCostUnit.php

@@ -6,9 +6,11 @@ use App\Domains\CostUnit\Actions\ChangeCostUnitDetails\ChangeCostUnitDetailsComm
 use App\Domains\CostUnit\Actions\ChangeCostUnitDetails\ChangeCostUnitDetailsRequest;
 use App\Domains\CostUnit\Actions\ChangeCostUnitState\ChangeCostUnitStateCommand;
 use App\Domains\CostUnit\Actions\ChangeCostUnitState\ChangeCostUnitStateRequest;
+use App\Mail\AdminMails\CostUnitInvalidBillingDeadlineMail;
 use App\Models\CostUnit;
 use App\Repositories\CostUnitRepository;
 use App\ValueObjects\Amount;
+use Illuminate\Support\Facades\Mail;
 
 class CloseCostUnit implements CronTask {
     public function handle(): void
@@ -33,6 +35,27 @@ class CloseCostUnit implements CronTask {
             }
 
             $billingEndTime = \DateTime::createFromFormat('Y-m-d H:i:s', $billingEnd);
+            if (false === $billingEndTime) {
+                $billingEndTime = \DateTime::createFromFormat('Y-m-d', $billingEnd);
+            }
+
+            if (false === $billingEndTime) {
+                $recipients = config('app.admin_mail');
+                if (null === $recipients) {
+                    $recipients = CostUnit::where('id', $costUnit['id'])->first()
+                        ?->treasurers()->pluck('email')->all() ?? [];
+                }
+
+                if (!empty($recipients)) {
+                    Mail::to($recipients)->send(new CostUnitInvalidBillingDeadlineMail(
+                        costUnitId: $costUnit['id'],
+                        costUnitName: $costUnit['name'] ?? null,
+                        invalidBillingDeadline: $billingEnd,
+                    ));
+                }
+
+                continue;
+            }
             $billingEndTime->setTime(0,0,0);
             $billingEndTime->add(new \DateInterval('P1D'));
 

app/Views/Components/Modal.vue

@@ -32,7 +32,7 @@
 </template>
 
 <script setup>
-import { ref, watch, onMounted, onUnmounted, nextTick } from 'vue'
+import {nextTick, onMounted, onUnmounted, ref, watch} from 'vue'
 
 const props = defineProps({
     show: Boolean,
@@ -115,7 +115,7 @@ onUnmounted(() => {
 }
 
 .modal-body {
-    max-height: 600px;
+    max-height: 80vh;
     overflow: auto;
 }
 

app/Views/Components/RichSelectBox.vue

@@ -1,9 +1,11 @@
 <script setup>
-import {computed, onBeforeUnmount, onMounted, ref} from 'vue'
+import {computed, nextTick, onBeforeUnmount, onMounted, ref} from 'vue'
 import Icon from './Icon.vue'
 
 // Generisches Custom-Dropdown, das je Option ein Icon + Label anzeigt (ein natives <select> kann
-// keine SVG-Icons rendern). Wiederverwendbar für Icon-/Rich-Selects.
+// keine SVG-Icons rendern). Die Options-Liste wird per <Teleport> an <body> gehängt und fixed
+// positioniert, damit sie nicht von einem Eltern-Container mit overflow (z. B. .tab-content in
+// TabbedPage) abgeschnitten wird. Wiederverwendbar für Icon-/Rich-Selects.
 const props = defineProps({
     // Ausgewählter Wert (value einer Option).
     modelValue: {type: String, default: ''},
@@ -15,11 +17,23 @@ const emit = defineEmits(['update:modelValue'])
 
 const open = ref(false)
 const root = ref(null)
+const listRef = ref(null)
+const pos = ref({top: 0, left: 0, width: 0})
 
 const selected = computed(() => props.options.find(o => o.value === props.modelValue) ?? null)
 
-function toggle() {
+function updatePosition() {
+    if (!root.value) return
+    const rect = root.value.getBoundingClientRect()
+    pos.value = {top: rect.bottom + 4, left: rect.left, width: rect.width}
+}
+
+async function toggle() {
     open.value = !open.value
+    if (open.value) {
+        await nextTick()
+        updatePosition()
+    }
 }
 
 function select(option) {
@@ -28,7 +42,9 @@ function select(option) {
 }
 
 function onClickOutside(event) {
-    if (root.value && !root.value.contains(event.target)) {
+    const inRoot = root.value && root.value.contains(event.target)
+    const inList = listRef.value && listRef.value.contains(event.target)
+    if (!inRoot && !inList) {
         open.value = false
     }
 }
@@ -39,13 +55,22 @@ function onKeydown(event) {
     }
 }
 
+function onReposition() {
+    if (open.value) updatePosition()
+}
+
 onMounted(() => {
     document.addEventListener('click', onClickOutside)
     document.addEventListener('keydown', onKeydown)
+    window.addEventListener('resize', onReposition)
+    // capture=true, damit auch Scrollen in inneren Containern die Position aktualisiert
+    window.addEventListener('scroll', onReposition, true)
 })
 onBeforeUnmount(() => {
     document.removeEventListener('click', onClickOutside)
     document.removeEventListener('keydown', onKeydown)
+    window.removeEventListener('resize', onReposition)
+    window.removeEventListener('scroll', onReposition, true)
 })
 </script>
 
@@ -67,7 +92,14 @@ onBeforeUnmount(() => {
             <span class="rich-select__caret" aria-hidden="true">▾</span>
         </button>
 
-        <ul v-if="open" class="rich-select__list" role="listbox">
+        <Teleport to="body">
+            <ul
+                v-if="open"
+                ref="listRef"
+                class="rich-select__list"
+                role="listbox"
+                :style="{ top: pos.top + 'px', left: pos.left + 'px', width: pos.width + 'px' }"
+            >
                 <li
                     v-for="option in options"
                     :key="option.value"
@@ -81,6 +113,7 @@ onBeforeUnmount(() => {
                     <span>{{ option.label }}</span>
                 </li>
             </ul>
+        </Teleport>
     </div>
 </template>
 
@@ -126,11 +159,8 @@ onBeforeUnmount(() => {
 }
 
 .rich-select__list {
-    position: absolute;
+    position: fixed;
-    z-index: 50;
+    z-index: 1000;
-    top: calc(100% + 4px);
-    left: 0;
-    right: 0;
     margin: 0;
     padding: 4px;
     list-style: none;
@@ -140,6 +170,7 @@ onBeforeUnmount(() => {
     box-shadow: 0 8px 24px rgba(0, 0, 0, 0.12);
     max-height: 260px;
     overflow: auto;
+    box-sizing: border-box;
 }
 
 .rich-select__option {

app/Views/Components/TabbedPage.vue

@@ -1,5 +1,5 @@
 <script setup>
-import { ref, shallowRef, onMounted } from "vue"
+import {onMounted, provide, ref, shallowRef} from "vue"
 
 const props = defineProps({
     tabs: {
@@ -55,6 +55,9 @@ async function selectTab(index) {
     }
 }
 
+// Kind-Komponenten (z. B. Leer-Zustands-Hinweise) können damit gezielt zu einem anderen Tab springen.
+provide('selectTab', selectTab)
+
 onMounted(() => {
     if (props.tabs.length > 0) {
         selectTab(props.subTabIndex)

config/app.php

@@ -15,6 +15,8 @@ return [
 
     'name' => env('APP_NAME', 'Laravel'),
 
+    'admin_mail' => env('APP_ADMIN_MAIL'),
+
     /*
     |--------------------------------------------------------------------------
     | Application Environment

database/migrations/2026_08_06_150000_add_tax_information_to_tenants.php

@@ -0,0 +1,29 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->boolean('tax_liable')->default(false);
+            $table->unsignedTinyInteger('vat_rate')->default(0);
+            $table->string('tax_exemption_reason')->nullable();
+            $table->text('tax_exemption_note')->nullable();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->dropColumn([
+                'tax_liable',
+                'vat_rate',
+                'tax_exemption_reason',
+                'tax_exemption_note',
+            ]);
+        });
+    }
+};

database/migrations/2026_08_06_160000_add_vat_pricing_mode_to_tenants.php

@@ -0,0 +1,21 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->string('vat_pricing_mode')->default('inclusive');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->dropColumn('vat_pricing_mode');
+        });
+    }
+};

database/migrations/2026_08_06_160010_add_tax_snapshot_to_events.php

@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * Friert die umsatzsteuerliche Grundlage bei Event-Anlage aus den Tenant-Einstellungen ein. Die Werte sind
+ * danach unveränderlich, damit Preisermittlung und spätere Rechnungen von späteren Tenant-Änderungen
+ * unberührt bleiben. Bestandsevents erhalten die Defaults (keine USt).
+ */
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            $table->boolean('tax_liable')->default(false);
+            $table->unsignedTinyInteger('vat_rate')->default(0);
+            $table->string('vat_pricing_mode')->default('inclusive');
+            $table->string('tax_exemption_reason')->nullable();
+            $table->text('tax_exemption_note')->nullable();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            $table->dropColumn([
+                'tax_liable',
+                'vat_rate',
+                'vat_pricing_mode',
+                'tax_exemption_reason',
+                'tax_exemption_note',
+            ]);
+        });
+    }
+};

database/migrations/2026_08_06_170000_create_tax_exemption_reasons.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::create('tax_exemption_reasons', function (Blueprint $table) {
+            $table->string('slug')->primary();
+            $table->string('name');
+            $table->text('invoice_text')->nullable();
+            $table->boolean('requires_note')->default(false);
+            $table->timestamps();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('tax_exemption_reasons');
+    }
+};

database/migrations/2026_08_06_170010_add_tax_exemption_reason_foreign_keys.php

@@ -0,0 +1,48 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * Befüllt die Referenztabelle mit den Befreiungsgründen (§ 14 Abs. 4 Nr. 8 UStG) und verknüpft danach den
+ * nullbaren Befreiungsgrund von Tenant und Event per Foreign Key. Das Seeding erfolgt hier (nicht im
+ * ProductionDataSeeder), damit die FK-Ziele auch auf bestehenden Datenbanken beim Migrieren existieren.
+ * Ein noch nicht konfigurierter Tenant hat keinen Grund (NULL).
+ */
+return new class extends Migration {
+    public function up(): void
+    {
+        $now = now();
+        DB::table('tax_exemption_reasons')->insertOrIgnore([
+            ['slug' => 'small_business', 'name' => 'Kleinunternehmer (§ 19 UStG)', 'invoice_text' => 'Gemäß § 19 UStG wird keine Umsatzsteuer berechnet.', 'requires_note' => false, 'created_at' => $now, 'updated_at' => $now],
+            ['slug' => 'education', 'name' => 'Bildungs-/Kursleistung (§ 4 Nr. 22a UStG)', 'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 22 Buchst. a UStG von der Umsatzsteuer befreit.', 'requires_note' => false, 'created_at' => $now, 'updated_at' => $now],
+            ['slug' => 'youth_welfare', 'name' => 'Kinder- und Jugendhilfe (§ 4 Nr. 25 UStG)', 'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 25 UStG von der Umsatzsteuer befreit.', 'requires_note' => false, 'created_at' => $now, 'updated_at' => $now],
+            ['slug' => 'custom', 'name' => 'Sonstiger Grund (Freitext)', 'invoice_text' => null, 'requires_note' => true, 'created_at' => $now, 'updated_at' => $now],
+        ]);
+
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->foreign('tax_exemption_reason')
+                ->references('slug')->on('tax_exemption_reasons')
+                ->restrictOnDelete()->cascadeOnUpdate();
+        });
+
+        Schema::table('events', function (Blueprint $table) {
+            $table->foreign('tax_exemption_reason')
+                ->references('slug')->on('tax_exemption_reasons')
+                ->restrictOnDelete()->cascadeOnUpdate();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('tenants', function (Blueprint $table) {
+            $table->dropForeign(['tax_exemption_reason']);
+        });
+
+        Schema::table('events', function (Blueprint $table) {
+            $table->dropForeign(['tax_exemption_reason']);
+        });
+    }
+};

database/migrations/2026_08_06_170020_refine_tax_exemption_reasons.php

@@ -0,0 +1,81 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\DB;
+use Illuminate\Support\Facades\Schema;
+
+/**
+ * Schärft die Befreiungsgründe: paragraphenbasierte Slugs, präzise Zitate (§ 4 Nr. 25 Buchst. a bzw.
+ * Nr. 22 Buchst. a), neuer Grund § 4 Nr. 24 (Jugendherbergen) und eine feste Anzeige-Reihenfolge.
+ * Slug-Renames kaskadieren über die FKs (ON UPDATE CASCADE) auf tenants/events.
+ */
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('tax_exemption_reasons', function (Blueprint $table) {
+            $table->unsignedSmallInteger('sort_order')->default(0);
+        });
+
+        // § 19 – nur Slug + Sortierung
+        DB::table('tax_exemption_reasons')->where('slug', 'small_business')->update([
+            'slug' => 'ustg_19',
+            'sort_order' => 10,
+        ]);
+
+        // § 4 Nr. 25 Buchst. a – präzises Zitat (Durchführung kultureller/sportlicher Veranstaltungen)
+        DB::table('tax_exemption_reasons')->where('slug', 'youth_welfare')->update([
+            'slug' => 'ustg_4_25a',
+            'name' => 'Jugendhilfe – Veranstaltungen (§ 4 Nr. 25 Buchst. a UStG)',
+            'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 25 Buchst. a UStG von der Umsatzsteuer befreit.',
+            'sort_order' => 30,
+        ]);
+
+        // § 4 Nr. 22 Buchst. a – korrekt benannt, ans Ende (vor Freitext)
+        DB::table('tax_exemption_reasons')->where('slug', 'education')->update([
+            'slug' => 'ustg_4_22a',
+            'name' => 'Vorträge/Kurse (§ 4 Nr. 22 Buchst. a UStG)',
+            'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 22 Buchst. a UStG von der Umsatzsteuer befreit.',
+            'sort_order' => 40,
+        ]);
+
+        // Freitext ans Ende
+        DB::table('tax_exemption_reasons')->where('slug', 'custom')->update([
+            'sort_order' => 50,
+        ]);
+
+        // § 4 Nr. 24 (Jugendherbergen) – neu
+        $now = now();
+        DB::table('tax_exemption_reasons')->insertOrIgnore([
+            [
+                'slug' => 'ustg_4_24',
+                'name' => 'Jugendherbergen (§ 4 Nr. 24 UStG)',
+                'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 24 UStG von der Umsatzsteuer befreit.',
+                'requires_note' => false,
+                'sort_order' => 20,
+                'created_at' => $now,
+                'updated_at' => $now,
+            ],
+        ]);
+    }
+
+    public function down(): void
+    {
+        DB::table('tax_exemption_reasons')->where('slug', 'ustg_4_24')->delete();
+        DB::table('tax_exemption_reasons')->where('slug', 'ustg_19')->update(['slug' => 'small_business']);
+        DB::table('tax_exemption_reasons')->where('slug', 'ustg_4_25a')->update([
+            'slug' => 'youth_welfare',
+            'name' => 'Kinder- und Jugendhilfe (§ 4 Nr. 25 UStG)',
+            'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 25 UStG von der Umsatzsteuer befreit.',
+        ]);
+        DB::table('tax_exemption_reasons')->where('slug', 'ustg_4_22a')->update([
+            'slug' => 'education',
+            'name' => 'Bildungs-/Kursleistung (§ 4 Nr. 22a UStG)',
+            'invoice_text' => 'Die Leistung ist gemäß § 4 Nr. 22 Buchst. a UStG von der Umsatzsteuer befreit.',
+        ]);
+
+        Schema::table('tax_exemption_reasons', function (Blueprint $table) {
+            $table->dropColumn('sort_order');
+        });
+    }
+};

database/migrations/2026_08_06_170030_default_tax_exemption_reason_jugendhilfe.php

@@ -0,0 +1,20 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Support\Facades\DB;
+
+/**
+ * Setzt den Standard-Befreiungsgrund neuer Tenants auf Jugendhilfe (§ 4 Nr. 25 Buchst. a). Der Wert
+ * existiert in tax_exemption_reasons, der FK bleibt gültig. Bestehende Zeilen bleiben unverändert.
+ */
+return new class extends Migration {
+    public function up(): void
+    {
+        DB::statement("ALTER TABLE tenants ALTER COLUMN tax_exemption_reason SET DEFAULT 'ustg_4_25a'");
+    }
+
+    public function down(): void
+    {
+        DB::statement('ALTER TABLE tenants ALTER COLUMN tax_exemption_reason DROP DEFAULT');
+    }
+};

database/migrations/2026_08_12_140010_add_participation_options_to_events.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            // Veranstaltungsspezifische Pflicht-Auswahlfragen (Teilnahmeoptionen), je Frage genau eine Option.
+            // Struktur: [ { key, label, options: [ { value, label } ] } ]
+            $table->json('participation_options')->nullable();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            $table->dropColumn('participation_options');
+        });
+    }
+};

database/migrations/2026_08_12_140020_create_event_participant_options.php

@@ -0,0 +1,35 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        // Gewählte Teilnahmeoptionen je Anmeldung -- eine Zeile pro beantworteter Frage.
+        // Frage-/Options-Label werden als Snapshot mitgespeichert, damit spätere Änderungen der
+        // Fragen-Definition am Event bestehende Anmeldungen/Auswertungen nicht verfälschen.
+        Schema::create('event_participant_options', function (Blueprint $table) {
+            $table->id();
+            $table->string('tenant');
+
+            $table->foreignId('event_id')->constrained('events', 'id')->cascadeOnDelete()->cascadeOnUpdate();
+            $table->foreignId('event_participant_id')->constrained('event_participants', 'id')->cascadeOnDelete()->cascadeOnUpdate();
+
+            $table->string('question_key');
+            $table->string('question_label');
+            $table->string('value');
+            $table->string('value_label');
+
+            $table->timestamps();
+
+            $table->foreign('tenant')->references('slug')->on('tenants')->restrictOnDelete()->cascadeOnUpdate();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('event_participant_options');
+    }
+};

database/migrations/2026_08_12_150010_add_addons_to_events.php

@@ -0,0 +1,23 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            // Buchbare Zusätze (Event-Addons) als Ja/Nein-Optionen mit Preis.
+            // Struktur: [ { key, title, description, price, flat } ]
+            $table->json('addons')->nullable();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('events', function (Blueprint $table) {
+            $table->dropColumn('addons');
+        });
+    }
+};

database/migrations/2026_08_12_150020_create_event_participant_addons.php

@@ -0,0 +1,36 @@
+<?php
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration {
+    public function up(): void
+    {
+        // Gewählte Zusätze je Anmeldung -- eine Zeile pro gebuchtem Addon.
+        // Titel/Preis/Betrag werden als Snapshot mitgespeichert (relevant für die spätere Rechnung).
+        Schema::create('event_participant_addons', function (Blueprint $table) {
+            $table->id();
+            $table->string('tenant');
+
+            $table->foreignId('event_id')->constrained('events', 'id')->cascadeOnDelete()->cascadeOnUpdate();
+            $table->foreignId('event_participant_id')->constrained('event_participants', 'id')->cascadeOnDelete()->cascadeOnUpdate();
+
+            $table->string('addon_key');
+            $table->string('title');
+            $table->float('price')->default(0);
+            $table->boolean('flat')->default(false);
+            $table->integer('days')->default(0);
+            $table->float('amount')->default(0);
+
+            $table->timestamps();
+
+            $table->foreign('tenant')->references('slug')->on('tenants')->restrictOnDelete()->cascadeOnUpdate();
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::dropIfExists('event_participant_addons');
+    }
+};

resources/views/emails/admin/cost_unit_invalid_billing_deadline.blade.php

@@ -0,0 +1,16 @@
+<!DOCTYPE html>
+<html>
+<body>
+<p>
+    Für die Kostenstelle "{{ $costUnitName }}" (ID {{ $costUnitId }}) konnte das Abrechnungsende
+    nicht verarbeitet werden.
+</p>
+<p>
+    Der hinterlegte Wert "{{ $invalidBillingDeadline }}" ist weder ein gültiges Datum noch ein
+    Datum mit Uhrzeit. Die automatische Verarbeitung dieser Kostenstelle wurde deshalb übersprungen.
+</p>
+<p>
+    Bitte prüft und korrigiert das Abrechnungsende dieser Kostenstelle.
+</p>
+</body>
+</html>

tests/Feature/EventVatPricingTest.php

@@ -0,0 +1,155 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Domains\Event\Actions\CreateEvent\CreateEventCommand;
+use App\Domains\Event\Actions\CreateEvent\CreateEventRequest;
+use App\Enumerations\EatingHabit;
+use App\Enumerations\ParticipationFeeType;
+use App\Models\Event;
+use App\Models\Tenant;
+use App\RelationModels\EventParticipationFee;
+use App\Resources\EventResource;
+use DateTime;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Illuminate\Support\Facades\DB;
+use Tests\TestCase;
+
+class EventVatPricingTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private Tenant $tenant;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->tenant = Tenant::create([
+            'slug' => 'tv',
+            'name' => 'Test',
+            'email' => 't@example.com',
+            'email_finance' => 'finance@example.com',
+            'url' => 'test.local',
+            'account_name' => 'Test e.V.',
+            'account_iban' => 'DE00',
+            'account_bic' => 'XY',
+            'city' => 'Stadt',
+            'postcode' => '00000',
+            'is_active_local_group' => true,
+            'has_active_instance' => true,
+        ]);
+
+        app()->instance('tenant', $this->tenant);
+
+        DB::table('participation_types')->insert(['slug' => 'participant', 'name' => 'Teilnehmer']);
+        DB::table('participation_fee_types')->insert(['slug' => 'fixed', 'name' => 'Fix']);
+        EatingHabit::create(['slug' => EatingHabit::EATING_HABIT_VEGAN, 'name' => 'Vegan']);
+        EatingHabit::create(['slug' => EatingHabit::EATING_HABIT_VEGETARIAN, 'name' => 'Vegetarisch']);
+    }
+
+    private function makeFee(float $amountStandard): EventParticipationFee
+    {
+        return EventParticipationFee::create([
+            'tenant' => $this->tenant->slug,
+            'type' => 'participant',
+            'name' => 'Standard',
+            'description' => null,
+            'amount_standard' => $amountStandard,
+            'amount_reduced' => null,
+            'amount_solidarity' => null,
+        ]);
+    }
+
+    private function makeEvent(bool $taxLiable, int $vatRate, string $mode, int $feeId): Event
+    {
+        return Event::create([
+            'tenant' => $this->tenant->slug,
+            'name' => 'Event',
+            'identifier' => 'evt-' . uniqid(),
+            'location' => 'Ort',
+            'postal_code' => '00000',
+            'email' => 'e@example.com',
+            'start_date' => '2026-09-01',
+            'end_date' => '2026-09-05',
+            'early_bird_end' => '2026-08-20',
+            'registration_final_end' => '2026-08-25',
+            'early_bird_end_amount_increase' => 0,
+            'account_owner' => 'Owner',
+            'account_iban' => 'DE00',
+            'participation_fee_type' => 'fixed',
+            'participation_fee_1' => $feeId,
+            'pay_per_day' => false,
+            'pay_direct' => false,
+            'tax_liable' => $taxLiable,
+            'vat_rate' => $vatRate,
+            'vat_pricing_mode' => $mode,
+        ]);
+    }
+
+    private function calculate(Event $event): float
+    {
+        return new EventResource($event)->calculateAmount(
+            'participant',
+            'standard',
+            new DateTime('2026-09-01'),
+            new DateTime('2026-09-01'),
+            false,
+        )->getAmount();
+    }
+
+    public function test_add_on_mode_adds_vat_on_top(): void
+    {
+        $event = $this->makeEvent(taxLiable: true, vatRate: 19, mode: 'add_on', feeId: $this->makeFee(100.0)->id);
+
+        $this->assertEqualsWithDelta(119.0, $this->calculate($event), 0.001);
+    }
+
+    public function test_inclusive_mode_keeps_amount(): void
+    {
+        $event = $this->makeEvent(taxLiable: true, vatRate: 19, mode: 'inclusive', feeId: $this->makeFee(100.0)->id);
+
+        $this->assertEqualsWithDelta(100.0, $this->calculate($event), 0.001);
+    }
+
+    public function test_not_liable_ignores_add_on_mode(): void
+    {
+        $event = $this->makeEvent(taxLiable: false, vatRate: 19, mode: 'add_on', feeId: $this->makeFee(100.0)->id);
+
+        $this->assertEqualsWithDelta(100.0, $this->calculate($event), 0.001);
+    }
+
+    public function test_create_event_snapshots_tenant_tax_config(): void
+    {
+        $this->tenant->update([
+            'tax_liable' => true,
+            'vat_rate' => 7,
+            'vat_pricing_mode' => 'add_on',
+            'tax_exemption_reason' => null,
+            'tax_exemption_note' => null,
+        ]);
+
+        $response = new CreateEventCommand(new CreateEventRequest(
+            name: 'Sommerlager',
+            location: 'Ort',
+            postalCode: '00000',
+            email: 'e@example.com',
+            begin: new DateTime('2026-09-01'),
+            end: new DateTime('2026-09-05'),
+            earlyBirdEnd: new DateTime('2026-08-20'),
+            registrationFinalEnd: new DateTime('2026-08-25'),
+            earlyBirdEndAmountIncrease: 0,
+            participationFeeType: ParticipationFeeType::where('slug', 'fixed')->first(),
+            accountOwner: 'Owner',
+            accountIban: 'DE00',
+            payPerDay: false,
+        ))->execute();
+
+        $this->assertTrue($response->success);
+
+        $event = $response->event->fresh();
+        $this->assertTrue($event->tax_liable);
+        $this->assertSame(7, $event->vat_rate);
+        $this->assertSame('add_on', $event->vat_pricing_mode);
+    }
+}

tests/Feature/TenantTaxInformationTest.php

@@ -0,0 +1,141 @@
+<?php
+
+namespace Tests\Feature;
+
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxAction;
+use App\Domains\Admin\Actions\UpdateTenantTax\UpdateTenantTaxRequest;
+use App\Enumerations\TaxExemptionReason;
+use App\Enumerations\VatPricingMode;
+use App\Models\Tenant;
+use Illuminate\Foundation\Testing\RefreshDatabase;
+use Tests\TestCase;
+
+class TenantTaxInformationTest extends TestCase
+{
+    use RefreshDatabase;
+
+    private Tenant $tenant;
+
+    protected function setUp(): void
+    {
+        parent::setUp();
+
+        $this->tenant = Tenant::create([
+            'slug' => 'tv',
+            'name' => 'Test',
+            'email' => 't@example.com',
+            'email_finance' => 'finance@example.com',
+            'url' => 'test.local',
+            'account_name' => 'Test e.V.',
+            'account_iban' => 'DE00',
+            'account_bic' => 'XY',
+            'city' => 'Stadt',
+            'postcode' => '00000',
+            'is_active_local_group' => true,
+            'has_active_instance' => true,
+        ]);
+
+        app()->instance('tenant', $this->tenant);
+    }
+
+    private function runAction(bool $taxLiable, int $vatRate, ?string $reason, ?string $note = null, string $mode = 'inclusive'): object
+    {
+        return new UpdateTenantTaxAction(new UpdateTenantTaxRequest(
+            tenant: $this->tenant,
+            taxLiable: $taxLiable,
+            vatRate: $vatRate,
+            exemptionReason: $reason ? TaxExemptionReason::where('slug', $reason)->first() : null,
+            exemptionNote: $note,
+            vatPricingMode: VatPricingMode::from($mode),
+        ))->execute();
+    }
+
+    public function test_taxable_sets_rate_and_clears_exemption(): void
+    {
+        $this->tenant->update(['tax_exemption_reason' => 'ustg_19', 'tax_exemption_note' => 'alt']);
+
+        $response = $this->runAction(taxLiable: true, vatRate: 7, reason: null);
+
+        $this->assertTrue($response->success);
+
+        $fresh = $this->tenant->fresh();
+        $this->assertTrue($fresh->tax_liable);
+        $this->assertSame(7, $fresh->vat_rate);
+        $this->assertNull($fresh->tax_exemption_reason);
+        $this->assertNull($fresh->tax_exemption_note);
+    }
+
+    public function test_exemption_reason_persists_and_clears_rate(): void
+    {
+        $response = $this->runAction(taxLiable: false, vatRate: 19, reason: 'ustg_4_25a');
+
+        $this->assertTrue($response->success);
+
+        $fresh = $this->tenant->fresh();
+        $this->assertFalse($fresh->tax_liable);
+        $this->assertSame(0, $fresh->vat_rate);
+        $this->assertSame('ustg_4_25a', $fresh->tax_exemption_reason);
+        $this->assertNull($fresh->tax_exemption_note);
+    }
+
+    public function test_invalid_exemption_reason_fails(): void
+    {
+        $response = $this->runAction(taxLiable: false, vatRate: 0, reason: 'not_a_reason');
+
+        $this->assertFalse($response->success);
+        // Unbekannter Slug wird nicht aufgelöst (null) → kein Speichern, Wert bleibt unverändert.
+        $this->assertNull($this->tenant->fresh()->tax_exemption_reason);
+    }
+
+    public function test_custom_reason_requires_note(): void
+    {
+        $missing = $this->runAction(taxLiable: false, vatRate: 0, reason: 'custom', note: '  ');
+        $this->assertFalse($missing->success);
+
+        $ok = $this->runAction(taxLiable: false, vatRate: 0, reason: 'custom', note: 'Individueller Grund');
+        $this->assertTrue($ok->success);
+        $this->assertSame('Individueller Grund', $this->tenant->fresh()->tax_exemption_note);
+    }
+
+    public function test_vat_rate_is_clamped(): void
+    {
+        $this->runAction(taxLiable: true, vatRate: 250, reason: null);
+        $this->assertSame(100, $this->tenant->fresh()->vat_rate);
+    }
+
+    public function test_pricing_mode_persists_when_liable(): void
+    {
+        $this->runAction(taxLiable: true, vatRate: 19, reason: null, mode: 'add_on');
+        $this->assertSame('add_on', $this->tenant->fresh()->vat_pricing_mode);
+    }
+
+    public function test_pricing_mode_resets_to_inclusive_when_exempt(): void
+    {
+        $this->runAction(taxLiable: false, vatRate: 0, reason: 'ustg_19', mode: 'add_on');
+        $this->assertSame('inclusive', $this->tenant->fresh()->vat_pricing_mode);
+    }
+
+    public function test_invoice_text_per_reason(): void
+    {
+        $this->assertSame(
+            'Gemäß § 19 UStG wird keine Umsatzsteuer berechnet.',
+            TaxExemptionReason::where('slug', 'ustg_19')->first()->invoiceText(),
+        );
+        $this->assertSame(
+            'Die Leistung ist gemäß § 4 Nr. 25 Buchst. a UStG von der Umsatzsteuer befreit.',
+            TaxExemptionReason::where('slug', 'ustg_4_25a')->first()->invoiceText(),
+        );
+        $this->assertSame(
+            'Die Leistung ist gemäß § 4 Nr. 24 UStG von der Umsatzsteuer befreit.',
+            TaxExemptionReason::where('slug', 'ustg_4_24')->first()->invoiceText(),
+        );
+        // Freitext-Grund liefert den mitgegebenen Text statt eines festen Rechnungshinweises.
+        $this->assertSame('Mein Text', TaxExemptionReason::where('slug', 'custom')->first()->invoiceText('Mein Text'));
+    }
+
+    public function test_options_are_ordered(): void
+    {
+        $slugs = array_column(TaxExemptionReason::options(), 'value');
+        $this->assertSame(['ustg_19', 'ustg_4_24', 'ustg_4_25a', 'ustg_4_22a', 'custom'], $slugs);
+    }
+}

version

@@ -1 +1 @@
-4.6.1
+4.7.0