What is my credit card security code? The credit card security code (CSC) is usually a 3- or 4-digit number, which is not part of the credit card number. The CSC is typically printed on the back of a credit card (usually in the signature field). Where do I find it? Visa/Mastercard and Discover 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 CSC. American Express 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 CSC.