Security Code (CVV)     What is it?   The security code is the card verification value (CVV) and is used to check a card's authenticity. It enables online fraud to be reduced and protects the security of users making internet payments.     Where to find it?   On cards issued by Visa and Mastercard, the CVV is the last three digits printed on the signature strip on the back of the card; on American Express cards, it is the four digits printed above the main card number on the front of the card.         Close this window