The security code is a security feature of Visa, MasterCard, Discover and American Express credit cards. By including it with your order, you help protect your account from fraud and provide one more way of being sure your order is legitimate.
For Visa, MasterCard & Discover customers, the security code is the 3-digit number located on the back of your credit card, usually at the top of the signature strip.
For American Express customers, look for the 4-digit number printed on the front of your card. Depending on which card you have, the number should be located in small type above your credit card's main number.