Discover how credit card validation codes work and protect against fraud. Learn about their placement, security role, and examples to secure online transactions.

A credit card authorization key is a secure code used to process transactions, confirming purchases and preventing fraud ...

Credit card security codes are three-digit codes on the back of your card (four-digits on the front if you have an American Express card) used to verify that have the physical card. You typically ...

Credit card purchases are assigned merchant category codes, or MCCs. These codes can affect how you earn rewards, like points or cash back. Many or all of the products on this page are from partners ...

When you make credit card purchases online or over the phone, you'll often need the card's security code to complete the transaction. The security code helps to protect you from credit card fraud and ...