How to find your Card Security Code on a Visa, MasterCard or Discover card
Turn the card over and look at the signature panel. You will find either the entire 16-digit card number OR just the last 4 digits, followed by the 3-digit number. That 3-digit number is your Card Security Code. If your CSC number has been scratched off or is not visible you will need to contact your credit card company or bank for additional information.

How to find your Card Security Code on an American Express Card
The Card Security Code is the 4 digit number located above the account number on the face of the card, sometimes on the left side and sometimes on the right. If your CSC number has been scratched off or is not visible you will need to contact your credit card company or bank for additional information.