A credit card security code, or verification number, is a three- or four-digit number that banks and other lenders use to provide one more layer of protection against fraud, explains the credit-scoring company Experian.
This number is also known on different cards as a card verification number or value (CVV), card security code (CSC), card validation code (CVC) and card identification (CID). Understanding how these work will help you complete transactions more quickly, including when making phone calls to your card issuer or purchases online.
Read More: What is a CVS Number?
Where It’s Located
On most cards, the security code is found on the back in the signature area, or just to the right of it. It might appear in a white box that's the last part of the signature line, or it might just appear at the end of the signature line.
On an American Express card, the card verification number is the four-digit sequence that appears in black on the front of the card, just above the last two numbers of your credit card.
Unlike the raised (embossed) numbers that make up your credit card numbers, your verification number is flat, printed ink only.
Some cards, like Citibank's ThankYou Preferred card, have the credit card number, expiration date and CVV number on the back of the card.
Read More: What Is CVV in a Debit Card?
What It’s Used For
What if someone uses their smartphone to take a picture of your credit card, such as when it's lying on a table waiting to be picked up by a restaurant server? The person now has your name as it appears on the card, your card number and the expiration date.
To prevent someone from making charges to your card who only has a picture of the front of the card (or who saw the information and memorized it), but not the physical card, lenders use the security code. This allows merchants to request it, usually requiring customers to flip the card over to read it, increasing the likelihood that the person making the transaction has the card in their hand.
In addition, even if you give a business permission to store your credit card information for future purchases, companies are not allowed to store your number. Therefore, if the store is hacked, the hackers don't have your security number and will have fewer places to use your credit card.
Read More: Do Credit Cards Have PIN Numbers?
It’s Not Your PIN
Your CVV is not your personal identification number, which is another layer of protection. A PIN is a number you choose and use when asked. A PIN is more often used for debit card transactions, or when you are using a credit card's online services or app. Unlike a CVV, which is assigned to you, PINs often have to be requested, or set, by the card owner.
Other Names for Card Verification Number
Other names of the security code include: card security code, or CSC; card validation value, or CVV, for Visa cards; card validation code, or CVC, for MasterCard cards; and card identification, or CID, for American Express and Discover cards.