The credit card security number is a 3 or 4 digit code printed on your credit card. This security number helps online merchants prevent the fraudulent use of your credit card by verifying the card is in your physical possession.
On most credit cards (Visa, Mastercard, JCB, etc.), you will find the 3-digit security number printed in the signature panel on the back of the card.
American Express cardholders will find the 4-digit security number printed above the card number on the front of the card.
* The credit card security number is NOT the same as the Mastercard SecureCode or Verified by Visa pin (if applicable). These services may provided by your card company or bank.