How to verify us zip code with region in checkout and my account address magento 2.3

Question

I want to verify customer enter zip code is correctly match with the region.

For example:

zip code:10001

Region: New york

If the customer enters the wrong zip code for the region, it throws an error "your zipcode and region need to match"

I think I need to use the USPS API.

I created an account in USPS API.

How to implement this functionality in the checkout page and my account save address page.

I followed this below link. But It doesn't work for me.

https://www.w3solver.com/magento-2-address-verification-using-usps-api-on-checkout/

Any help, experience and knowledge sharing would be appreciated

Answer 1

You have put the postcode/Region checking at

\Magento\Quote\Model\ShippingMethodManagement::estimateByExtendedAddress \Magento\Quote\Model\ShippingMethodManagement::estimateByAddressId

because of these functions, the shipping methods are rendered at the checkout page.

Note that, Magento 2 does not save the Shipping address till database 's quote until select the Shipping method .

So, the above two methods is best way to checking ZipCode/region at checkout.