The CID (card identification) number is a 3- or 4-digit code found on your credit card. We are requesting it as an added security precaution. It's another measure we take to ensure that your credit card is present when you place your order. If your CID number is illegible, call your credit card company.
Visa, MasterCard and Discover Cards:
The CID (card identification) number is the 3-digit value printed on the signature panel on the back of Visa, MasterCard and Discover Cards immediately following the credit card account number.
Last 3 digits on back of card.
American Express Cards:
The CID (card identification) number is the 4-digit, non-embossed number printed above your account number on the face of your card.
Extra 4 digits on front of card.