What is the Card Security Code?
The Card Security Code (CSC) provides credit card customers with an additional level of security. The CSC code requires physical access to the credit card therefore reducing the risk of Internet credit card fraud.
Visa, Master Card, and Discover
The CSC code is the 3-digit code located after the credit card number on the signature strip of Visa, Master Card, and Discover cards (see example).
American Express cardholders can locate a 4-digit code on the front of the card above the account number. This code serves the same purpose as a CSC code.