Installation

1. First install Gravity Forms.
2. In the WordPress admin panel, go to [Plugins] in the left navigation menu.
3. Click the [Add New] button and upload the plugin (.zip file)
4. Activate the plugin
5. Create a Gravity Form
   • Add or edit a standard field [Single Line Text]
     • Check the “Input Mask” option
     • Select IBAN from the dropdown menu
   • Or; Add an advanced field [IBAN]

IBAN mask length

(optional) You can set the max length of the IBAN mask in the Single Line Text field.
Default this is set to 32 since that is the length of IBAN numbers for Saint Lucia and Nicaragua. To override this default you can set it to 18 (NL) or 22 (DE) for example.

Beware! If you set this to 18 and someone needs to fill in an IBAN of 22, that will not work and that might throw your visitor/client off.

Open wp-config.php and replace the following comment:

/* That’s all, stop editing! Happy blogging. */

…with the following piece of code:

define('GF_IBAN_LENGTH', '22');
/* That's all, stop editing! Happy blogging. */

IBAN custom mask

(optional) You can also change the way the maks is shown by using a WordPress filter. You can, for example, remove all spaces from the mask.

For this to keep working we strongly advise you to use a Child Theme (read official WordPress docs ») so your changes are not lost when your theme updates.

Open [child-theme]/functions.php and add the following code to the bottom of that file:

add_filter( "gform_input_mask_script", function($script, $form_id, $field_id, $mask) {
    if ($mask == "iban") {
        $mask_length = defined('GF_IBAN_LENGTH') ? (int) constant('GF_IBAN_LENGTH') : 18;
        $mask_string = rtrim( chunk_split( str_repeat( '*', $mask_length - 4), 4, ''), '');
        $script = "jQuery('#input_{$form_id}_{$field_id}').css('text-transform','uppercase').mask('aa99?{$mask_string}');";
    }
    return $script;
}, 10, 4 );

Disable php-iban requirement (compatibility with WooCommerce Germanized)

(optional) You can disable the requirement of the php-iban library when it’s already loaded in another plugin.

Open wp-config.php and replace the following comment:

/* That’s all, stop editing! Happy blogging. */

…with the following piece of code:

define('GF_IBAN_PHPIBAN', false);
/* That's all, stop editing! Happy blogging. */

Screenshots