diff --git a/app/Domains/Event/Controllers/DetailsController.php b/app/Domains/Event/Controllers/DetailsController.php
index a197c4e..fc3f735 100644
--- a/app/Domains/Event/Controllers/DetailsController.php
+++ b/app/Domains/Event/Controllers/DetailsController.php
@@ -224,6 +224,9 @@ class DetailsController extends CommonController {
             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;
diff --git a/app/Domains/Event/Views/Details.vue b/app/Domains/Event/Views/Details.vue
index fc57a06..6476ad8 100644
--- a/app/Domains/Event/Views/Details.vue
+++ b/app/Domains/Event/Views/Details.vue
@@ -5,6 +5,7 @@ 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({
@@ -37,16 +38,16 @@ const tabs = [
         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(() => {
diff --git a/app/Domains/Event/Views/Partials/ParticipantsByAddon.vue b/app/Domains/Event/Views/Partials/ParticipantsByAddon.vue
new file mode 100644
index 0000000..7753814
--- /dev/null
+++ b/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>
diff --git a/app/Repositories/EventParticipantRepository.php b/app/Repositories/EventParticipantRepository.php
index ea184ab..efba1e6 100644
--- a/app/Repositories/EventParticipantRepository.php
+++ b/app/Repositories/EventParticipantRepository.php
@@ -141,6 +141,44 @@ class EventParticipantRepository {
         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 = [];