diff --git a/app/Domains/Event/Controllers/SignupController.php b/app/Domains/Event/Controllers/SignupController.php
index 00df3d7..01bcd6d 100644
--- a/app/Domains/Event/Controllers/SignupController.php
+++ b/app/Domains/Event/Controllers/SignupController.php
@@ -68,6 +68,11 @@ class SignupController extends CommonController {
 
     public function signUp(int $eventId, Request $request) {
         $event = $this->events->getById($eventId, false);
+
+        if (!$event->registration_allowed || new \DateTime() > $event->start_date) {
+            return response()->json(['status' => 'closed'], 403);
+        }
+
         $eventResource = $event->toResource();
         $registrationData = $request->input('registration_data');
         $siblingReduction = $registrationData['sibling'] === 'true';
diff --git a/app/Domains/Event/Views/Signup.vue b/app/Domains/Event/Views/Signup.vue
index b0bd3ba..a941154 100644
--- a/app/Domains/Event/Views/Signup.vue
+++ b/app/Domains/Event/Views/Signup.vue
@@ -99,10 +99,14 @@ function close() {
 
             <div class="signup-body">
                 <SignupForm
+                    v-if="props.event.registrationAllowed"
                     :event="props.event"
                     :participantData="props.participantData ?? {}"
                     :localGroups="props.localGroups ?? []"
                 />
+                <p v-else class="signup-closed-notice">
+                    Die Anmeldung für diese Veranstaltung ist geschlossen.
+                </p>
             </div>
 
         </shadowed-box>
@@ -220,6 +224,14 @@ function close() {
     word-break: break-all;
 }
 
+.signup-closed-notice {
+    text-align: center;
+    padding: 24px;
+    color: #991b1b;
+    font-weight: 600;
+    font-size: 1rem;
+}
+
 /* ─── Tablet (640–1023px) ─── */
 @media (max-width: 1023px) {
     .signup-box {
diff --git a/app/Domains/Invoice/Controllers/EditController.php b/app/Domains/Invoice/Controllers/EditController.php
index e8e3c28..3dbec7b 100644
--- a/app/Domains/Invoice/Controllers/EditController.php
+++ b/app/Domains/Invoice/Controllers/EditController.php
@@ -65,7 +65,7 @@ class EditController extends CommonController{
         $currentEvents = $this->costUnits->getCostUnitsForNewInvoice(CostUnitType::COST_UNIT_TYPE_EVENT);
 
         return response()->json([
-            'invoice' => new InvoiceResource($invoice)->toArray(),
+            'invoice' => new InvoiceResource($newInvoice)->toArray(),
             'status' => 'success',
             'costUnits' => array_merge($runningJobs, $currentEvents),
         ]);
diff --git a/app/Resources/EventResource.php b/app/Resources/EventResource.php
index eef36db..72b373b 100644
--- a/app/Resources/EventResource.php
+++ b/app/Resources/EventResource.php
@@ -34,7 +34,7 @@ class EventResource extends JsonResource{
             'accountIban' => $this->event->account_iban,
             'alcoholicsAge' => $this->event->alcoholics_age,
             'sendWeeklyReports' => $this->event->send_weekly_report,
-            'registrationAllowed' => $this->event->registration_allowed,
+            'registrationAllowed' => $this->event->registration_allowed && new \DateTime() <= $this->event->start_date,
             'archived' => $this->event->archived,
             'earlyBirdEnd' => ['internal' => $this->event->early_bird_end->format('Y-m-d'), 'formatted' => $this->event->early_bird_end->format('d.m.Y')],
             'registrationFinalEnd' => ['internal' => $this->event->registration_final_end->format('Y-m-d'), 'formatted' => $this->event->registration_final_end->format('d.m.Y')],
diff --git a/version b/version
index 6cedcff..4e298cc 100644
--- a/version
+++ b/version
@@ -1 +1 @@
-4.5.2
+4.5.3