If your card has been declined, it could be that you have entered your card details incorrectly. Cards may also be declined if the name and billing address you have entered do not match the information held by your bank or card provider. Occasionally, overly zealous fraud protection by your bank or provider can also see your card declined. Check that you have entered all details correctly and that you have sufficient funds in your account. If this is the case, contact your bank or card provider.