If you pay your account with a card that is not registered at your address, such as a business card or one that is registered to another address, you may have problems when making payments using your normal contact details.
To add an additional billing address that is used when making payments, login to your control panel and choose Add Contact on the menu.
Fill out the details of the contact you wish to add, which would match the registered address for the card you wish to pay with.
Once your additional has been accepted, you can then click on 'Your Details' on the right menu and then select your newly created contact from the Billing / Card Details drop down.
Any future card payments will be made with this address which you can add, modify or remove at any point by following the same steps.