About a security code (CVV) for credit cards
A security code (CVV) is three or four digits of numbers printed on a credit card.
For customers using VISA, Master, JCB, or Diners
The security code (CVV) is a three-digit number printed on the far right of your signature in the back of your credit card.
For customers using American Express
The security code is a four-digit number that is listed on the surface of the credit card to the upper right corner of the card number.