Платежный адрес клиента WooCommerce

Что ж, это довольно просто. Ваш код должен быть таким:

/* ---------------------- Registration page ----------------------- */

/* Add extra fields in registration form */
add_action( 'woocommerce_register_form_start', 'my_extra_register_fields' );
function my_extra_register_fields() {
?>
    <p class="woocommerce-FormRow woocommerce-FormRow--wide form-row form-row-wide">
        <label for="reg_billing_vat"><?php _e( 'Billing VAT', 'woocommerce' ); ?><span class="required">*</span></label>
        <input type="text" class="input-text" name="billing_vat" id="reg_billing_vat" value="<?php if ( ! empty( $_POST['billing_vat'] ) ) esc_attr_e( $_POST['billing_vat'] ); ?>">
    </p>
    <div class="clearfix"></div>
<?php
}

/* registration form fields Validation */
add_action( 'woocommerce_register_post', 'my_validate_extra_register_fields', 10, 3 );
function my_validate_extra_register_fields( $username, $email, $validation_errors ) {

    if ( isset( $_POST['billing_vat'] ) && empty( $_POST['billing_vat'] ) ) {
        $validation_errors->add( 'billing_vat_error', __( 'VAT number is required!', 'woocommerce' ) );
    }   

    return $validation_errors;
}

/* Below code save extra fields when new user register */
add_action( 'woocommerce_created_customer', 'my_save_extra_register_fields' ); 
function my_save_extra_register_fields( $customer_id ) {

    if ( isset( $_POST['billing_vat'] ) ) {     

        // VAT field which is used in WooCommerce
        update_user_meta( $customer_id, 'billing_vat', sanitize_text_field( $_POST['billing_first_name'] ) );
    }

}


/* ---------------------- Account page ----------------------- */

/* Show custom fields on Account details page */
add_action( 'woocommerce_edit_account_form', 'my_woocommerce_edit_account_form' );
function my_woocommerce_edit_account_form() {
    $user_id = get_current_user_id();
    $user    = get_userdata( $user_id );

    if ( !$user ) return;

    $billing_vat = get_user_meta( $user_id, 'billing_vat', true );
?>
    <fieldset>
        <legend>Custom information</legend>

        <p class="woocommerce-FormRow woocommerce-FormRow--wide form-row form-row-wide">
            <label for="billing_vat">Billing VAT</label>
            <input type="text" name="billing_vat" id="billing_vat" value="<?php echo esc_attr( $billing_vat ); ?>" class="input-text" />
        </p>
        <div class="clearfix"></div>

    </fieldset>
   <?php
}

/* Below code save extra fields when account details page form submitted */
add_action( 'woocommerce_save_account_details', 'my_woocommerce_save_account_details' );
function my_woocommerce_save_account_details( $user_id ) {

    if ( isset( $_POST['billing_vat'] ) ) {
        update_user_meta( $user_id, 'billing_vat', sanitize_text_field( $_POST['billing_vat'] ) );
    }

}

Вы можете добавить больше настраиваемых полей в соответствии с вашими потребностями.

И да, вы можете добавлять настраиваемые поля в my-account/edit-address/billing/, используя ловушку фильтра woocommerce_billing_fields.

Таким образом, код для этого должен быть таким, как показано ниже:

/* Add field under my account billing  */
add_filter( 'woocommerce_billing_fields', 'my_woocommerce_billing_fields' );
function my_woocommerce_billing_fields( $fields ) {

    $user_id = get_current_user_id();
    $user    = get_userdata( $user_id );

    if ( !$user ) return;

    $fields['billing_vat'] = array(
        'type'      => 'text',
        'label'     => __('VAT', 'woocommerce'),
        'placeholder'   => _x('VAT Number', 'placeholder', 'woocommerce'),
        'required'  => true,
        'class'     => array('form-row'),
        'clear'     => true,
        'default'   => get_user_meta( $user_id, 'billing_vat', true ) // assing default value if any
    );

    return $fields;
}

/* Format custom field to show on my account billing  */
add_filter( 'woocommerce_my_account_my_address_formatted_address', 'custom_my_account_my_address_formatted_address', 10, 3 );
function custom_my_account_my_address_formatted_address( $fields, $customer_id, $name ) {

    $fields['vat']  = get_user_meta( $customer_id, $name . '_vat', true );

    return $fields;
}

/* Replace the key for custom field to show on my account billing  */
add_filter( 'woocommerce_formatted_address_replacements', 'custom_formatted_address_replacements', 10, 2 );
function custom_formatted_address_replacements( $address, $args ) {
    $address['{vat}'] = '';

    if ( ! empty( $args['vat'] ) ) {
        $address['{vat}'] = __( 'VAT Number', 'woocommerce' ) . ': ' . $args['vat'];
    }

    return $address;
}   
add_filter( 'woocommerce_localisation_address_formats', 'custom_localisation_address_format' );
function custom_localisation_address_format( $formats ) {

    foreach($formats as $key => $value) :
        $formats[$key] .= "\n\n{vat}";
    endforeach;

    return $formats;
}