Credit Card Security Code
A three or four digit code on your credit card, separate from the 16 digit card number.
The location varies slightly depending on your type of card:
On the reverse side of your card, 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.
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 Security Code.