Reply To: Limit number of checkboxes that can be selected

• John Huebner

• October 18, 2017 at 2:06 am

add_filter('acf/validate_value/name=your_field_name', 'only_allow_3', 20, 4);
function only_allow_3($valid, $value, $field, $input) {
  if (count($value) > 3) {
    $valid = 'Only Select 3';
  }
  return $valid;
}

https://www.advancedcustomfields.com/resources/acf-validate_value/