With any online credit card transaction, the challenge is to ensure the authenticity of the credit card number, and ensure that it's being used only by the owner of the card. Unfortunately, credit card numbers are often stored by online vendors to simplify the ordering process for their regular customers. To make the process more secure, many vendors are now requiring that you enter a security code, often called the Credit Verification Value or CVV, is printed on the card, but is never (by law) stored on the merchant's system. So, while it requires an additional step to complete the purchase, security of the transaction is improved - for both the vendor and the card holder.
Where do I find my CVV?
Depending upon the card you're using, the CVV will be located in one of two spots:
Visa / MasterCard
Visa and MasterCard use a three‑digit CVV, printed on the rear of the card near or on the signature strip.
American Express
American Express uses a four-digit code called a Card Identification Number (CID), which is printed on the front of the card, usually on the right side. (Some special‑program Amex cards have the CID printed on the left side.)
