diff --git a/backend/src/routes/adminEvents.js b/backend/src/routes/adminEvents.js
index adcf5557..ebd27507 100644
--- a/backend/src/routes/adminEvents.js
+++ b/backend/src/routes/adminEvents.js
@@ -1237,14 +1237,13 @@ router.put('/:id', adminAuth, requirePermission('events.edit'), requireEventOwne
     }
 
     // Enforce expires_at requirement based on app settings
-    if (Object.prototype.hasOwnProperty.call(updates, 'expires_at')) {
-      if (!updates.expires_at) {
-        const fieldReqs = await getEventFieldRequirements();
-        if (fieldReqs.require_expiration) {
-          return res.status(400).json({ error: 'Expiration date is required.' });
-        }
-        updates.expires_at = null;
-      }
+    // Allow admins to clear `expires_at` on edit even when the global
+    // `event_require_expiration` setting is ON (#426). The setting now
+    // controls only the create-time default — once an event exists, an
+    // admin editing it can override and remove the expiration. Empty /
+    // null values normalize to NULL in the column ("never expires").
+    if (Object.prototype.hasOwnProperty.call(updates, 'expires_at') && !updates.expires_at) {
+      updates.expires_at = null;
     }
 
     // Format hero logo settings if provided
diff --git a/frontend/src/pages/admin/EventDetailsPage.tsx b/frontend/src/pages/admin/EventDetailsPage.tsx
index f29ec14e..fc00bb8c 100644
--- a/frontend/src/pages/admin/EventDetailsPage.tsx
+++ b/frontend/src/pages/admin/EventDetailsPage.tsx
@@ -459,7 +459,6 @@ export const EventDetailsPage: React.FC = () => {
   }, [showMediaFilter, photoFilters.media_type]);
 
   const { data: publicSettings } = usePublicSettings();
-  const requireExpiration = publicSettings?.event_require_expiration !== false;
   const phoneFieldEnabled = publicSettings?.event_phone_field_enabled === true;
 
   // Fetch categories for the event
@@ -686,10 +685,11 @@ export const EventDetailsPage: React.FC = () => {
       return;
     }
 
-    if (requireExpiration && !editForm.expires_at) {
-      toast.error(t('validation.expirationRequired', 'Expiration date is required.'));
-      return;
-    }
+    // No expiration-required validation on edit (#426). The global
+    // `event_require_expiration` setting only enforces a default at
+    // create-time — once an event exists, an admin can clear the
+    // expiration via this form. The matching backend gate was dropped
+    // in adminEvents.js.
 
     // Clean up the data - remove undefined values
     const updateData: any = {