Visa/Mastercard and Discover Users Flip your card over
and look at the signature box. You should see either the entire 16-digit credit
card number or just the last four digits followed by a special 3-digit code.
This 3-digit code is your Card Security Code.
American Express Credit Card Users Look for
the 4-digit code printed on the front of your card just above and to the right
of your main credit card number. This 4-digit code is your Card Identification
Number (CID). The CID is the four-digit code printed just above the Account