Card Security Code (CSC) - The CSC code number for VISA and MasterCard is the last three digits of the printed number on the back of your credit card in the signature area. The CID code number for American Express is the printed four digit number located on the front of the card slightly above the account number.

The CSC/CID number is used to help reduce credit card fraud as an individual must have the card in their posession in order to obtain this number.