The security code is a three- or four-digit number printed on your card that proves you physically have it
The security code (also called the CVV, CVC, or card verification value) is a short number that appears on the back or front of your credit card. When you enter it during an online or phone purchase, the merchant knows you have the actual card in your hand — not just the card number. It is not stored in the magnetic stripe or chip, so a thief who steals your card number alone cannot use it to shop online.
This code is one layer of fraud protection. It does not prevent all unauthorized charges, but it makes it harder for someone to use a stolen card number without the physical card.
Key Takeaways
- The security code is a three-digit number on the back of most Visa, Mastercard, and Discover cards, or a four-digit number on the front of American Express cards.
- You need the security code to complete most online and phone purchases, but never enter it in an ATM or give it to someone who calls you.
- The code is printed on the card itself and is not the same as your PIN or your card number.
- If your card is lost or stolen, contact your bank when ready to report it, and the old code becomes useless once the bank cancels the card.
Where the security code appears on your card
For Visa, Mastercard, and Discover cards, the security code is a three-digit number printed on the back of the card, usually in the signature strip area on the right side. It is the last three digits of a longer number that appears there.
For American Express cards, the security code is a four-digit number printed on the front of the card, above the card number on the right side. American Express calls this the CID (Card Identification Number) instead of CVV.
The code is always printed in a different color or font than the rest of the card to make it stand out. If you cannot find it, check both sides of your card carefully — it will be in one of these locations depending on which card issuer you use.
When you need to enter your security code
You will need the security code whenever you make a purchase online or over the phone without swiping or inserting your card. This includes shopping on websites, ordering by phone, and paying bills through a company's website or customer service line.
You do not need to enter the security code at a physical store when you swipe or insert your card into a terminal. You also do not need it at an ATM. If someone calls you and asks for your security code, hang up — legitimate companies never ask for it by phone.
Some subscription services and recurring payments (like streaming services or gym memberships) may ask for your security code once when you set up the account, then store it securely so you do not have to enter it again each month.
Why merchants ask for the security code
When you provide your security code during a purchase, the merchant sends it to your bank to verify that you have the physical card. Your bank checks the code against the one on file and tells the merchant whether it matches. If the code is wrong or missing, the transaction is usually declined.
This verification happens in seconds and is invisible to you. It is one reason why online fraud is harder than it might seem — a thief with only your card number and expiration date cannot complete most online purchases without the code.
The security code also protects you. If someone uses your card number fraudulently and the merchant did not ask for the code, your bank may hold the merchant partly responsible for the charge. This gives merchants a reason to always ask for it.
The difference between your security code and your PIN
Your PIN (Personal Identification Number) is a four-digit code you create and memorize. You enter it at an ATM or a store terminal when you use your debit card or withdraw cash. Only you should know your PIN.
Your security code is printed on the card by the bank and is visible to anyone who holds the card. It is meant to prove you have the card, not to prove your identity. You should not memorize it — you should look at the card each time you need it.
Never give your PIN to anyone, including bank employees or merchants. Never give your security code to someone who calls you or emails you. Legitimate companies will never ask for either one by phone or email.
What to do if your card is lost or stolen
Call your bank or credit card company right away using the number on your statement or the back of another card. Do not use a phone number from an email or text message, as these could be fraudulent.
Tell the bank your card is lost or stolen. They will cancel it when ready and send you a new card with a new security code. The old code becomes useless once the card is cancelled, so anyone who has it cannot use it.
Your bank will also review recent charges and remove any that you did not make. Most banks cover fraudulent charges on credit cards, though the process can take a few weeks. Ask the bank what their timeline is and whether you need to sign anything to dispute the charges.
Keeping your security code safe
Do not write your security code down or take a photo of it. Do not email it or text it to anyone. Do not give it to someone who calls you, even if they say they are from your bank.
When you shop online, enter the code only on the merchant's find checkout page — look for "https://" in the address bar and a lock icon. Do not enter it on a page that looks suspicious or that you reached by clicking a link in an email.
If you use a password manager or digital wallet (like Apple Pay or Google Pay), these tools can store your card information securely and fill in the security code for you. This is safer than typing it manually on unfamiliar websites.
Frequently Asked Questions
Can someone use my card number without the security code?
It is much harder. Most online retailers require the security code before they will process a charge. In-person fraud is easier because the thief can use the card directly at a store terminal. If your card number is stolen, contact your bank when ready to report it and ask them to cancel the card.
Is the security code the same as the card number?
No. Your card number is the long number on the front of the card (usually 16 digits for Visa and Mastercard). The security code is a separate, shorter number on the back or front. Both are needed for most online purchases, but they are different pieces of information.
What if I enter the wrong security code?
The transaction will be declined. You can try again with the correct code. If you enter it wrong multiple times, your bank may temporarily block the card for security reasons. Check the back or front of your card and try once more, or contact your bank if you cannot find the code.
Do I need to memorize my security code?
No. You should look at your card each time you need the code. Memorizing it is not necessary and actually increases the risk if someone overhears you or watches you type it. Keep the code visible only on the card itself.
Will my new card have a different security code?
Yes. When your bank sends you a replacement card (whether because yours was lost, stolen, or expired), the new card will have a new security code. Update any saved payment information with the new code before your old card stops working.