What is a Credit Card Verification Number?

The card verification number is a security requirement implemented by credit card companies to help reduce fraud for internet, phone or mail transactions. Since the card verification number is listed on your credit card but not stored anywhere, the only way to have the card verification number is to physically have possession of the credit card.

Where can I find the card verification number on my credit card?

The card verification number for American Express is the 4 digits printed (not embossed) on the front of the card. It is always located above the credit card number. In some instances, the card verification number is located on the left side of the card, but is always above the account number. Some cards have a four-digit number embossed below the account number, but this is not the card verification number.
The card verification number for a MasterCard, Visa, or Discover is the last 3 digits of the number in the signature area on the back of your card.