What is a credit card number?

Ever wondered what the numbers on your credit card mean? Each of those digits is necessary for transactions to take place. The numbers are used to authenticate things like the identity of the cardholder and the credit card issuer.

Credit card numbers follow a formula that’s based on the credit card issuer and network. Learn more about what these numbers mean.

Key takeaways

  • Credit card numbers identify the credit card network, credit card issuer and cardholder.
  • Other numbers you might see on a credit card are the security code and expiration date.
  • Because of potential credit card scams, it’s important to help protect yourself from fraud.
  • Some credit card issuers allow you to use virtual card numbers, which can help protect your credit card information when making online purchases.

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What are credit card numbers and how do they work?

A credit card number is the 15- or 16-digit number found on the front or back of a credit card. It identifies several things, including:

  • The credit card network: The four major credit card networks in the U.S. are Visa®, Mastercard®, American Express® and Discover®. These networks communicate between merchants and credit card issuers to facilitate credit card purchases. 
  • The credit card issuer: A credit card issuer is a financial institution, like Capital One and other banks and credit unions, that provides credit to cardholders. Two of the major credit card networks, American Express and Discover, are also credit card issuers.
  • The cardholder: The cardholder is the person to whom a credit card is issued. 

The number on your credit card is different from your account number, although the two are linked. For example, if your credit card is lost or stolen, you’ll receive a new card with a different credit card number. But the account number will stay the same. 

How many numbers are on a credit card?

A typical credit card number is 15 or 16 digits long. But you may see some as short as eight digits and others as long as 19 digits. Credit cards also include other numbers, such as security codes and expiration dates.

Where is the credit card number?

You should see a string of digits placed across the credit card in groups of three or four. This is your credit card number. It may be located on the front or the back of the card.

What do credit card numbers mean?

While they might seem random, each digit on your credit card is important for making purchases. Some digits have specific meanings. And others work as identifiers when grouped together. 

Typically, the first six to eight digits, referred to as the bank identification number (BIN) or issuer identification number (IIN), identify the card issuer. The remaining digits identify the individual account of the cardholder. 

Because each digit has meaning, it’s crucial to protect your credit card number. Avoid writing down or taking photos of the number, and always report a lost or stolen credit card to the card issuer.

Here’s a breakdown of what the individual numbers mean:

A graphic of the numbers commonly shown on the front of a credit card.

First numbers: industry identifier

The first digit on a credit card will tell you two things: the credit card network and the industry associated with the card. This chart lists the numbers’ corresponding networks:

First digit of credit card number Credit card network
2 or 5 Mastercard
3 American Express
4 Visa
6 Discover

Besides the payment network, the first digit also identifies which industry the card is associated with. This digit is the major industry identifier (MII). Some common MIIs include:

First digit of credit card number Industry
1-2 Air travel and financial services
2-6 Credit card networks
7 Petroleum
8 Healthcare and telecommunications
9 Government and "other" category


Identification numbers

The next five to seven digits form the rest of the BIN. In most cases, by combining the first through the sixth or eighth digits, you can figure out what the payment network and card issuer are—and the industry they’re associated with. 

Account identifier

The rest of the digits form a unique sequence to identify the account and cardholder. This number may change if you get a new card.

Last number: checksum

The last digit is known as the checksum or check digit. During the transaction process, this number is quickly plugged into a formula called the Luhn algorithm and used to ensure the card number is valid.

A graphic of the front and back of a typical credit card.

Other numbers on a credit card

The credit card number isn’t the only important information on your credit card. Here are some other numbers you’ll see:

  • Expiration dates: Help prevent credit card fraud by adding another level of verification during purchases. And because credit cards suffer wear and tear, the expiration date ensures you get a fresh card, with any new security measures, every few years. Expiration dates are generally formatted with two digits for the month and two digits for the year, separated by a forward slash. An expiration of September 2025 would look like 09/25 on your card, for example. And it means the card should be active through the last day of September 2025.
  • Security code: Sometimes called the card verification value (CVV) or card verification code (CVC), this three- or four-digit number is an added level of verification for remote purchases. Retailers aren’t able to store CVV numbers, which means the code can help protect your credit account in case of a data breach. The security code can be found on the front or back of the card, depending on the issuer.

If this sounds like what you see on your debit card too, you’re right. Debit card numbers work a lot like credit card numbers, including the part about card networks, banks and cardholder identification.

How do people steal credit card numbers?

While credit cards are designed to help keep your information secure, there are a few common scams to be aware of:

  • Phishing: Phishing scams are fraudulent emails, texts or calls that try to get your personal information. A phishing attempt might involve leading you to a fake website where you’ll be asked for sign-in details or personal information to verify your identity.
  • Public Wi-Fi: Unsecured public internet networks can put your information at risk. Avoid entering private information like account numbers or opening sensitive documents without using a virtual private network (VPN).
  • Data breaches: Large organizations can be targeted by hackers who steal credit card numbers and other personal information.
  • ATM skimming: A credit card skimmer is a device that can steal credit card numbers and PINs from ATMs and other public card terminals.
  • Trashed documents: Bills or bank statements in your trash may also be a risk if a fraudster goes through your trash.

How to protect your credit card information

Here are some ways to help protect yourself from credit card fraud:

Monitor your account information online and offline

Monitoring your credit scores, reports and credit card statements can help you spot suspicious activity. Keep an eye out for any transactions you didn’t make.

If you hold on to physical documents, store them in a secure location. You can also shred papers before they’re tossed in the trash. And if you cancel a credit card account, make sure to destroy the card before throwing it away.

Boost your digital defenses

Using a VPN on your computer or smartphone can help prevent others from stealing your financial information through a public Wi-Fi network. Strong passwords for each of your online accounts can also help. And you could enable two-factor authentication for even more protection.

Use a virtual card number

Virtual card numbers are another way to keep your credit card account more secure. These are unique credit card numbers linked to your credit card account that allow you to shop online without giving merchants your actual credit card number.

Credit card numbers in a nutshell

Credit card numbers identify the credit card issuer, credit card network and cardholder associated with the card. Curious about more ways to keep yourself and your account information safe? Learn how to protect your digital identity.

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