diff --git a/src/layouts/service-zip/service-zip.vue b/src/layouts/service-zip/service-zip.vue
index 88d160077..b01f99c06 100644
--- a/src/layouts/service-zip/service-zip.vue
+++ b/src/layouts/service-zip/service-zip.vue
@@ -149,7 +149,7 @@ export default {
                         );
                     }
 
-                    if (store.getters.externalParameterCustomer.phoneNumber) {
+                    if (store.getters.externalParameterCustomer?.phoneNumber) {
                         await baseMixin.methods.dispatchStoreAction(
                             storeActions.SAVE_PHONE_NUMBER,
                             store.getters.externalParameterCustomer.phoneNumber,