Card Identification Number
The Card Identification Number (Card ID) is required for the Visa, Mastercard, and American Express. The Discover/Novus card does not require a Card ID.
The Card ID is an added security feature to help protect you against online fraud.
The Card Identification Number is the group of numbers immediately following your credit card number on the back of the card. These Card ID numbers are used by your credit card company to help prevent fraud. Because the Card ID number is not printed on your receipts, it helps ensure that someone is not using your credit card information fraudulently.
For Visa and Mastercard there are 3 digits on the back of the card in the area shown by the graphic above.
For American Express there are 4 digits on the front of the card in the area shown by the graphic above.
Note: The digits are printed on your card, rather then stamped in the plastic like the digits in your credit card number on the front side of your card.