Card Security Code (CSC / CVV / CVC / CVN)

The Card Security Code, also known as the Card Verification Value (CVV), Card Verification Code (CVC), or Card Verification Number (CVN), is a three- or four-digit code printed on payment and credit cards. It is an additional security feature used to verify the legitimacy of a card during card-not-present (CNP) transactions.

What Is a Card Security Code?

The Card Security Code (CSC) is a 3- or 4-digit number used to verify that the person making a transaction actually possesses the card. It’s an extra layer of protection that helps prevent unauthorized use of your card number, especially in online, mobile, or phone-based purchases.

Unlike the card number or expiration date, the CSC is not stored on the card’s magnetic stripe or chip and is not printed on receipts—making it harder for thieves to copy.

Where to Find the Card Security Code

Depending on your card type, the CSC may appear in different locations:

• Visa, Mastercard, Discover: The CSC is a 3-digit code on the back of the card, usually next to the signature panel.
• American Express: The CSC is a 4-digit code printed on the front of the card, above the card number.

This code is printed only, not raised or embedded in the card’s magnetic strip or chip.

Alternative Names for the Card Security Code

These terms all refer to the same security feature, designed to protect your card in digital transactions.

Is the Card Security Code Stored?

No. Merchants are not allowed to store your CSC/CVV after a transaction is processed. This rule is part of the PCI DSS (Payment Card Industry Data Security Standards), which helps protect consumers from data breaches and fraud.

Even if a retailer is hacked, the stolen data won’t include your CSC—limiting the damage fraudsters can do.

Related Security Terms You Should Know

• PCI Compliance: A set of standards that ensure businesses securely process and store credit card data.
• Card-Not-Present (CNP): Any transaction where the card is not physically present (e.g., online or phone).
• Tokenization: Replaces your card number with a random code (token) during digital payments for added security.
• EMV Chip: A smart chip on modern cards that encrypts transactions in-store.
• CVV Mismatch: When the CSC entered doesn’t match the one on file—can trigger fraud alerts or decline a transaction.

Why the Card Security Code Matters

Using the CSC/CVV code is one of the simplest yet most effective ways to reduce the risk of credit card fraud. For consumers, it’s an extra checkpoint of safety. For merchants, it’s a crucial part of preventing chargebacks and protecting customer trust.

Key Takeaways:

• The Card Security Code (CSC) is a 3- or 4-digit code used to verify ownership of a credit or debit card.
• It is not stored by merchants and should be kept private.
• It goes by many names: CVV, CVC, CID, and CVN.
• It plays a vital role in securing online and card-not-present transactions.