As you know WooCommerce uses the “order ID” (which is also the ID of the order post in the database) as the order number. This displays in the “WooCommerce” > “Orders” table, on each line of the order, under the “Order ” column, as well as the order “quick view” window, the single order page and the customer’s My Account page.
But what if you need to add a prefix or a suffix to this number, so that this is in line with your business or invoice requirements?
Here’s the fix – enjoy!

PHP Snippet: Add Prefix and/or Suffix to WooCommerce Order Numbers
In the snippet below, I’m simply adding text before and after the order ID. Simply edit or remove the strings to display prefix and/or suffix.
/**
* @snippet Order Number Prefix/Suffix
* @how-to Get CustomizeWoo.com FREE
* @author Rodolfo Melogli
* @compatible WooCommerce 8
* @donate $9 https://businessbloomer.com/bloomer-armada/
*/
add_filter( 'woocommerce_order_number', 'bbloomer_order_number_prefix', 9999, 2 );
function bbloomer_order_number_prefix( $order_id, $order ) {
return 'Prefix-' . $order_id . '-suffix';
}