We typically see this occur if you have moved recently or if you're using your school address instead of your home address. Our advice is for you to contact your financial institution and verify the information they have and that it's current. You may want to ask about the failed transaction(s) and inquire as to the status of those funds.
For international credit cards
Some international credit cards will not work in our system if the billing information cannot be verified. We're told that's a possible reason for failed transactions. We recommend that you contact your financial institution for more information.