What if the Shipping destination provided during Checkout does not match the location selected in cart?

Here's how the various payment processors' Checkout methods can handle a mismatch when the Shipping destination provided during Checkout differs from the country or postal/ZIP code specified in the cart:

PayPal Payments Standard & PayPal Payments Pro Express Checkout:

PayPal's checkout site calls back to our server to automatically recalculate Shipping based on the actual Shipping address provided during Checkout.

If you wish, your PayPal Business account settings allow you to block specific countries from being able to complete a checkout at all. You can find these settings in your PayPal Business account under Profile > My Selling Tools > Managing risk and fraud, where you would select the Country Monitor and click Edit, then Add the countries you wish to block, choose to Decline them, then click the Save button.

You should also select permitted countries in your E-junkie Dashboard under Manage Shipping & Tax > Shipping Preferences > Limit Shipping Destinations list. By combining those settings, there should be no chance for a buyer to select a blocked destination country, neither in the cart before checkout nor during checkout itself.

PayPal Payments Pro Direct Payment, PayPal Payments Advanced, Authorize.Net & 2Checkout:

We control the Checkout page behavior for these card-based methods, so we can pass the country and zip/postal code selected in the cart along to the Checkout page where it cannot be altered without going back to the cart; thus, there is no chance of a mismatch in these Checkout methods.

ClickBank:

This Checkout method is only available with instant-checkout Buy Now buttons, so it does not use the E-junkie cart where a country could be selected incorrectly.