diff --git a/src/components/01_branch-management/FormBranchInformation.vue b/src/components/01_branch-management/FormBranchInformation.vue
index 9c8e0607..508d8c83 100644
--- a/src/components/01_branch-management/FormBranchInformation.vue
+++ b/src/components/01_branch-management/FormBranchInformation.vue
@@ -155,8 +155,10 @@ function formatCode(input: string | undefined, type: 'code' | 'number') {
               ? $t('branch.form.headofficeNameEN')
               : $t('branch.form.branchNameEN')
           "
-          :rules="[(val) => val && /^[A-Za-z]+$/.test(val)]"
-          :error-message="$t('form.error.required')"
+          :rules="[
+            (val) => !!val || $t('form.error.required'),
+            (val) => /^[A-Za-z]+$/.test(val) || $t('form.error.letterOnly'),
+          ]"
           for="input-name-en"
         />