The card identification number is an important security feature that helps validate
the customer placing the order actually has the card in his/her possession, and
that the account is legitimate.
VISA & Master Cards
The card identification number is a 3-digit non-embossed number printed on the signature
panel on the back of the card immediately following the card account number.
Discover Card
The card identification number is the 3-digit, non-embossed number printed on the
signature panel on the back of the card immediately following the card account number.
American Express
On American Express cards, the card identification number is a 4 digit, non-embossed
number printed just above and to the right of your account number on the front of
the card.