This code snippet is a Wordpress / Woocommerce PHP function called validate_mobile_number() that validates a mobile phone number submitted via a form. Please insert it into your theme's functions.php file.
Here's an explanation of how it works:

  1. The function first retrieves the mobile phone number from the billing_phone field in the $_POST superglobal array.

  2. It defines an array $valid_formats that contains regular expressions representing valid mobile phone number formats. In this case, the formats are +35385xxxxxxx, +35386xxxxxxx, and +35387xxxxxxx, and +35383xxxxxxx.

  3. The function then iterates over each format in the $valid_formats array using a foreach loop.

  4. For each format, it uses the preg_match() function to check if the billing_mobile_number matches the format. If a match is found, the function immediately returns true, indicating that the mobile number is valid.

  5. If none of the formats match the billing_mobile_number, the function proceeds to the next format in the loop.

  6. After the loop completes without finding a match, it executes the wc_add_notice() function. This function is typically used in the context of a WooCommerce store and displays an error notice to the user, indicating that the mobile number format is incorrect.

The error notice message states:  "Please correct the format of your mobile number: +35385xxxxxxx or +35386xxxxxxx or +35387xxxxxxx or +35383xxxxxxx.")


add_action( 'woocommerce_checkout_process', 'validate_mobile_number' );


function validate_mobile_number() {

    $billing_mobile_number = $_POST['billing_phone'];

    $valid_formats = array('/^\+35385[0-9]{7}$/', '/^\+35386[0-9]{7}$/', '/^\+35383[0-9]{7}$/', '/^\+35387[0-9]{7}$/');


    foreach ($valid_formats as $format) {

        if (preg_match($format, $billing_mobile_number)) {

            return true;




    wc_add_notice( __( 'Please correct the format of your mobile number: +35385xxxxxxx or +35386xxxxxxx or +35387xxxxxxx or +35383xxxxxxx.' ), 'error' );




This snippet can be used in a form validation process within a WordPress or WooCommerce environment to ensure that the mobile number is in the specified valid formats.
Please modify the format according to the conventions used in your country.