Yes, it can. American Express cards have a 4-digit CVV code on the front. On the back, like other credit cards, there is also a 3-digit CVV code.
Since customers, out of habit, usually use the 3-digit security code,
- it would be useful for websites to check CVV entry based on the card scheme (MasterCard, Visa, TROY, etc.), supporting both 3-digit and 4-digit CVV entry, and to set the CVV field to 4 digits for card schemes that use a 4-digit CVV.
- banks need to design their systems to accept both the 4-digit CVV on the front and the 3-digit CVV on the back for American Express card transactions.
How should the payment form be designed?
On American Express cards, the four-digit code appears on the front; this code may be labeled differently from the three-digit code used on Visa and Mastercard. The form can guess the scheme from the first digits of the card number and open a field of the appropriate length.
Forcing the same length for every scheme can prevent Amex users from completing a transaction. On the other hand, showing a clear help text for users trying to enter the three-digit code from the back reduces the error rate.
The security code must never be recorded or written to log files under any circumstances.
