The credit card Security Code, also called the Bank code or the Card Identification Number (CIN), is a special security code feature on the American Express, Diner's Club, Discover, MasterCard or Visa credit card.

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 the credit card Security Code.

MasterCard
Flip your card over and look at the signature box. You should see a 16-digit credit card number followed by a special 3-digit code. This 3-digit code is the credit card Security Code.

Visa
Flip your card over and look at the signature box. You should see a 16-digit credit card number followed by a special 3-digit code. This 3-digit code is the credit card Security Code.

Discover
Flip your card over and look at the signature box. You should see a 16-digit credit card number followed by a special 3-digit code. This 3-digit code is credit card Security Code, like VISA and MasterCard.