diff --git a/frontend/src/pages/OnOffboardingPage.jsx b/frontend/src/pages/OnOffboardingPage.jsx
index 4194411..dc292ca 100644
--- a/frontend/src/pages/OnOffboardingPage.jsx
+++ b/frontend/src/pages/OnOffboardingPage.jsx
@@ -416,6 +416,12 @@ const OnOffboardingPage = () => {
     };
 
     const completeOn = async () => {
+        const relevantProcesses = onProcesses.filter(p => !editingOn?.department || p.department_name === editingOn.department);
+        const unchecked = relevantProcesses.filter(p => !onForm.checklist_data[`proc_${p.id}`]);
+        if (unchecked.length > 0) {
+            toast.error(`Noch ${unchecked.length} Aufgabe(n) offen — bitte zuerst alle Punkte abhaken.`);
+            return;
+        }
         try {
             await onboardingService.update(editingOn.id, { status: 'completed', checklist_data: onForm.checklist_data, notes: onForm.notes, completion_date: today() });
             toast.success('Onboarding abgeschlossen!');
@@ -513,6 +519,14 @@ const OnOffboardingPage = () => {
     };
 
     const completeOff = async () => {
+        const relevantProcesses = offProcesses.filter((p, i, arr) =>
+            arr.findIndex(x => x.responsible_team === p.responsible_team && x.title === p.title) === i
+        );
+        const unchecked = relevantProcesses.filter(p => !offForm.checklist_data[`proc_${p.id}`]);
+        if (unchecked.length > 0) {
+            toast.error(`Noch ${unchecked.length} Aufgabe(n) offen — bitte zuerst alle Punkte abhaken.`);
+            return;
+        }
         try {
             await offboardingService.update(editingOff.id, { status: 'completed', checklist_data: offForm.checklist_data, notes: offForm.notes, completion_date: today() });
             toast.success('Offboarding abgeschlossen!');