The wpforms_process_validate_payment-coupon action fires validation on the Coupon form field when the form is submitted.


(int) Field ID.
(array) Original raw/unsanitized field value submitted for the field.
(array) Processed form settings/data, prepared to be used later.



More Information

The wpforms_process_validate_payment-coupon action is applied to the Coupon form field for checking the amount of the coupon, as an example is above a particular amount set in the function.


In this example, we’re preventing any form submission if the coupon flat rate amount is less than 1.00.

 * Do not allow to submit coupons lower than 1.00.
 * @link https://wpforms.com/developers/wpforms_process_validate_payment-coupon/
 * @param int     $field_id        Field ID.
 * @param array   $field_submit    Unsanitized field value submitted for the field.
 * @param array   $form_data       Form data and settings.

function wpf_discard_low_coupons( $field_id, $field_submit, $form_data ) {

	$coupon = wpforms_coupons()->get( 'repository' )->get_coupon_by_code( $field_submit );

	if ( $coupon === null ) {

	$currency = wpforms_get_currency();

	if ( $coupon->get_discount_type() === 'flat' && (float) $coupon->get_discount_amount() <= 1.00 ) {
		wpforms()->get( 'process' )->errors[ $form_data[ 'id' ] ][ $field_id ] = sprintf( /* translators: %s - Currency code name. */
			esc_html__( 'Coupon amount is less that 1.00 %s. Please, use another one.', 'your-translation-domain' ),
add_action( "wpforms_process_validate_payment-coupon", 'wpf_discard_low_coupons', 10, 3 );

Article Reference: How to Restrict Coupons by Amount