Woocommerce Checkout Zip code or Pin code Field Validation

In case you receive lot of incorrect zip code, postal code or pin code entered in the billing or shipping address fields of woocommerce powered ecommerce website, you can limit the zip code field digits to validate it properly. For instance if in your country zip code is of minimum 4, 5, or 6 digits, then you can use woocommerce checkout process function add_action code to validate it for correct zip code entry by your customers.

So, here is code. which you can add in your theme’s functions.php file of your active child theme (or theme).Save file and testing in your checkout page!

In this code validate the zip code field for at least 6 digit number. If the entered number is less than or greater than 6 digits then it will show the error message and if it is correct it will let the checkout process complete. You can change the number to 4,5,6 or any other number depending on your country’s zip codes.

add_action('woocommerce_checkout_process', 'my_custom_checkout_field_process');
  
function my_custom_checkout_field_process() {
    global $woocommerce;
  
    // Check if set, if its not set add an error. This one is only requite for companies
    if ( ! (preg_match('/^[0-9]{6}$/D', $_POST['billing_postcode'] ))){
        wc_add_notice( "Incorrect Zip code! Please enter correct number."  ,'error' );
    }
}