1) Incorrect details entered: The vast majority of declined orders are due to differences between the billing name and address entered and those which are kept on file by your credit card company.
2) Security Code: The incorrect security code has been entered during the payment process.
3) Insufficient Funds: There may be a lack of funds in your account or not enough credit available to cover the payment.
4) Non legality of card: The card in use may have expired, been cancelled or blocked.
5) Fraud Watch: A payment may be declined by the credit card company to protect you from what it may consider to be a fraudulent transaction. Reasons for this may include the size of the transaction or the time of day the transaction has taken place.
6) Daily Purchase Limit exceeded: To protect users from fraudulent charges, most credit cards have a limit on how much debt can be accumulated during a 24 hour period. If this amount is exceeded then your credit card company may have blocked your account from any further activity and the card payment will be declined.
7) Technical Problems: There may be network issues (yours or ours) preventing card payments taking place.