M frontend/containers/NewTravelDialog/index.tsx → frontend/containers/NewTravelDialog/index.tsx

@@ -58,7 +58,7 @@ const [dateError, setDateError] = useState(false);
   const [titleError, setTitleError] = useState(false);
   const [isTitleEmpty, setIsTitleEmpty] = useState(true);
 
-  const canCreate = !!name && !!seats && !phoneError;
+  const canCreate = !!name && !!seats && !phoneError && phone;
 
   const clearState = () => {
     setName('');

M frontend/containers/Travel/HeaderEditing.tsx → frontend/containers/Travel/HeaderEditing.tsx

@@ -207,7 +207,7 @@ variant="contained"
           color="primary"
           onClick={onSave}
           id="TravelSave"
-          disabled={phoneError}
+          disabled={phoneError || !phone}
         >
           {t('generic.save')}
         </Button>