First, please check that you have enough funds in your account. If you are paying by credit card, verify that your card details are entered correctly, especially the CVC number and expiration date. You should also make sure you know your 3-D Secure password. 3-D Secure is a system used by credit card companies that provides an additional layer of security for online payments. Incorrect 3-D Secure answers are the primary reason for your bank not honoring your payment. If you do not know your settings, or if your payment keeps on being rejected, please contact your bank.