diff --git a/src/main/java/de/assecutor/votianlt/pages/view/AddJobView.java b/src/main/java/de/assecutor/votianlt/pages/view/AddJobView.java
index 85eedb7..b08955b 100644
--- a/src/main/java/de/assecutor/votianlt/pages/view/AddJobView.java
+++ b/src/main/java/de/assecutor/votianlt/pages/view/AddJobView.java
@@ -139,6 +139,7 @@ public class AddJobView extends Main {
         customerSelection = new ComboBox<>("Auftraggeber/Rechnungsempfänger");
         customerSelection.setPlaceholder("Wählen Sie einen Auftraggeber aus...");
         customerSelection.setWidthFull();
+        customerSelection.setRequiredIndicatorVisible(true);
         // Mit Kunden des angemeldeten Benutzers befüllen und Mapping aufbauen
         List<Customer> ownerCustomers = customerService.findAllForCurrentOwner();
         customerLabelToEntity.clear();
@@ -653,8 +654,12 @@ public class AddJobView extends Main {
                 .asRequired("")
                 .bind(Job::getDeliveryDate, Job::setDeliveryDate);
 
+        // Bind customerSelection field with validation
+        binder.forField(customerSelection)
+                .asRequired("Auftraggeber/Rechnungsempfänger ist erforderlich")
+                .bind(Job::getCustomerSelection, Job::setCustomerSelection);
+
         // Bind optional fields without validation
-        binder.bind(customerSelection, Job::getCustomerSelection, Job::setCustomerSelection);
         binder.bind(pickupCompany, Job::getPickupCompany, Job::setPickupCompany);
         binder.bind(pickupSalutation, Job::getPickupSalutation, Job::setPickupSalutation);
         binder.bind(pickupPhone, Job::getPickupPhone, Job::setPickupPhone);
@@ -691,6 +696,12 @@ public class AddJobView extends Main {
             pickupDate, deliveryDate
         };
 
+        // Add validation listener for customerSelection ComboBox
+        customerSelection.addValueChangeListener(event -> {
+            triggerValidation();
+            updateTabLabels();
+        });
+
         // Add value change listeners to trigger validation on every change for text fields
         for (TextField field : requiredTextFields) {
             field.addValueChangeListener(event -> {
@@ -775,6 +786,9 @@ public class AddJobView extends Main {
     }
 
     private boolean hasAddressValidationErrors() {
+        // Check customer selection
+        boolean customerSelectionEmpty = customerSelection.getValue() == null || customerSelection.getValue().trim().isEmpty();
+        
         // Check pickup address fields
         boolean pickupErrors = isFieldEmpty(pickupFirstName) || isFieldEmpty(pickupLastName) ||
                               isFieldEmpty(pickupStreet) || isFieldEmpty(pickupHouseNumber) ||
@@ -785,7 +799,7 @@ public class AddJobView extends Main {
                                isFieldEmpty(deliveryStreet) || isFieldEmpty(deliveryHouseNumber) ||
                                isFieldEmpty(deliveryZip) || isFieldEmpty(deliveryCity);
 
-        return pickupErrors || deliveryErrors;
+        return customerSelectionEmpty || pickupErrors || deliveryErrors;
     }
 
     private boolean hasAppointmentValidationErrors() {