What Is a CVV Number?
4 Min Read | Last updated: October 14, 2024
This article contains general information and is not intended to provide information that is specific to American Express products and services. Similar products and services offered by different companies will have different features and you should always read about product details before acquiring any financial product.
CVV numbers are the extra 3- or 4-digit numbers on credit or debit cards. They provide an added layer of security by ensuring the buyer has physical access to their card.
At-A-Glance
- A CVV number is the extra three- or four-digit number printed on your credit or debit card.
- Though CVV stands for “Card Verification Value,” you might also know this series of digits as a CVC, CSC, CVN, or CID, depending on the card issuer.
- CVV numbers are usually used by online merchants to verify that the buyer has physical access to the card.
If you’ve ever made an online purchase, you’ve probably had to enter your CVV — that three- or four-digit number that’s on your card but isn’t part of the 15 or 16 digits you know as your “card number.” Maybe you’ve seen it written as your CVC, CVN, or CID, or simply referred to as your credit card security code.
But what exactly is a CVV number and why is it important? Here’s what you need to know.
What Is a Card CVV?
A CVV is the three- or four-digit security code that commonly appears on the back of your card near your signature, though some card issuers print it on the front. CVV numbers are typically shown in printed text, even if the credit card number itself is written in raised numerals.
CVV stands for “Card Verification Value.” (Yes, saying “CVV number” is a bit redundant, but that’s the common usage. And hey — it’s not as redundant as “PIN number” or “ATM machine”!)
Besides CVV, there are many other names for this card security code, including:
- CVC — Card Verification Code or Card Validation Code.
- CSC — Card Security Code.
- CVN — Card Verification Number.
- CID — Card Identification number.
Your CVV number should not be confused with your personal identification number, or PIN. Entered on a keypad, a PIN is used to validate in-person transactions, usually in conjunction with a chip embedded in your debit or credit card.2 In the U.S., it’s typically more common for debit cards to use PINs. Many credit cards do not, but some card issuers let you set up a PIN as an added layer of protection.
Why Are CVV Numbers Important and What Do They Do?
CVV numbers protect you. They provide an extra layer of security against someone taking your credit card number and using it in unauthorized ways. For example, retailers can store customers’ credit card numbers to make future purchases easier, but they can’t store CVV numbers after purchase or transaction authorization.3 If a website or merchant asks you for your CVV number, they’re taking an extra step to confirm you physically have access to the card and aren’t using a number stolen from a data breach or a photo of the card — assuming the credit card number and CVV number are on opposite sides of the card.
This is why you might be asked to supply a CVV number when using a new shipping address, even if you’re using a saved card number. After all, stolen credit card numbers aren’t typically used to send purchases to the rightful owner of that credit card, so an unfamiliar address is more likely to trigger a request for additional verification.4
What Don’t CVV Numbers Do?
Though they play an important role in keeping your transactions secure, CVV numbers are only one component of card security: They’re merely a way to verify the purchaser has physical access to the card. Therefore, they’re primarily important in transactions that take place online and over the phone, not in person. For added in-person security, cards rely on signatures, magnetic strips, and EMV chips. For more on how credit cards work, check out “How Do Credit Cards Work? Demystifying Credit Art & Science.”
Nor do CVV numbers protect you against phishing scams in which someone tries to trick you into giving away your card number and card security code. The best way to protect your number is to disclose it only to people and businesses you trust — and only for transactions that you initiate. If you think your card number or CVV code has been compromised in some way, contact your card issuer immediately. They can get you a replacement with a new number and CVV code, if necessary.
Finally, checking CVV numbers is primarily a step merchants can take to protect transactions from fraud. But retailers aren’t required to check CVV numbers, even if all their business is online — and some may never check at all.5 As a shopper, it’s important to practice good credit card security practices, like only shopping on websites with URLs that include “HTTPS” and never giving out your CVV or card information in response to an email or phone call.
A Brief History of CVV Numbers
CVV numbers were created in large part to help make online shopping more secure.5 The rise in online shopping was likely the single biggest driver in adoption — especially for customers who had their card access interrupted any time its authenticity was mistakenly called into question. By adding another means of authentication, CVV numbers made online credit card transactions more reliable and convenient.
Frequently Asked Questions
The number of digits is a decision made by the payment network.1 Many payment networks use three-digit numbers, but four-digit numbers work the same way and are harder to guess. American Express, for example, uses a four-digit card identification code.
When retailers process your card payment, they can ask for your CVV number. This triggers a check to make sure your card number and CVV match. If they don’t match, it usually means one of three things: The buyer is using a stolen credit card number, the buyer is using an older card that has expired or been replaced, or the buyer made a typo. The retailer may store your credit card number for future purchases, but they won’t store your CVV after a purchase is authorized.3
Not easily. By randomly guessing, there’s a 1-in-1,000 chance of guessing a three-digit code, and a 1-in-10,000 chance of guessing a four-digit code. Merchants generally won’t allow too many guesses, locking out would-be scammers after a few tries. If a fraudster guesses correctly, alert your card issuer immediately. They should send you a card with a new card number and a new CVV number.
The Takeaway
CVV numbers are the extra three or four digits on a credit card. Known by many names, they are an important element of credit card security. By using data that businesses can’t store to provide additional verification for purchases made online or over the phone, CVV numbers help keep transactions safe.
1 “How Many Numbers Are on a Credit Card?,” Experian
2 “Using Debit Cards,” Consumer.gov
3 “FAQ: Can card verification codes/values be stored for card-on-file or recurring transactions?,” PCI Security Standards Council
4 “11 Signs Your Credit Card Has Been Hacked,” Experian
5 “What is the CVV number?,” AP News
Matt Crespi is a writer, consultant, and social science researcher focused on innovation, policy, and organizational behavior. He earned his PhD in Public Policy and Management at Carnegie Mellon University, where he co-founded the Corporate Startup Lab.
All Credit Intel content is written by freelance authors and commissioned and paid for by American Express.
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The material made available for you on this website, Credit Intel, is for informational purposes only and intended for U.S. residents and is not intended to provide legal, tax or financial advice. If you have questions, please consult your own professional legal, tax and financial advisors.
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