Zip Code validation on WooCommerce Checkout Page

Good Evening – I need help validating the zip code field on the checkout page.

Example: If a customer selects “NJ” but enters a “NJ” zip code the order is processed. Currently using “multiple Addresses” by WooCommerce and this is a MUST for the client. However, we need to validate that the zip code is correct before processing the order.

The page I need help with: [log in to see the link]