Our card processor validates the zip/postal code associated with your card. Please make sure the flag on the checkout page matches the country the card is associated with. If you are using a prepaid card, most companies require you to register the prepaid card and add an address. You can find the website to register and add the address on the back of the card. If you are still experiencing issues signing up, you are always welcome to call us and we can set up the account with you on the phone. Our phone number is 800-548-4647 or 801-627-2000. Office hours are Monday-Friday 9am-5pm MST.