What is a Security Code?
The card security code is a three-digit number (four-digit on American Express)
printed on your credit card. This number is not embossed on the card and hence
not printed on receipts - making it difficult for anyone other than the genuine cardholder
to know it and to use it.
You will find this three-digit security code
printed at the top of the signature strip
on the reverse side of Visa, MasterCard
and Discover Card credit cards.
You will find this four-digit security code
on the front of American Express cards,
above the account number.