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 ...

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

If you find a lost card, either turn it in to an employee of the business where you found it, return it to a branch of its affiliated bank or call the customer support number on the back of the card.