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/zipcode specified in the cart:
- PayPal Payments Standard, PayPal Payments Pro Express Checkout & Google Checkout:
Shipping is automatically recalculated based on the actual Shipping address provided during Checkout.
If you wish, your PayPal account settings allow you to block specific countries from being able to complete a checkout at all (consult PayPal help pages or support staff for more info about this setting); you should also select permitted countries in your E-junkie Seller Admin > Cart Shipping Settings > 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, Authorize.Net & E-junkie Free Checkout:
We control the Checkout page behavior for these 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.
- 2CheckOut & ClickBank:
These Checkout methods are only available as instant-checkout Buy Now buttons, so they do not use the E-junkie cart where a country could be selected incorrectly.