What Are Credit Card Numbers & What Do They Mean?

Did you know the numbers on a credit card aren’t random and have specific meanings?


Have you ever wondered what the numbers on your credit card mean? Believe it or not, each of those digits is necessary for your transactions to take place. They’re used to authenticate things like the identities of the cardholder and issuer.

Credit card numbers follow a standard formula. Keep reading to learn what each digit means. 

What Is a Credit Card Number?

A credit card number is often the 15- or 16-digit number found on the front or back of your credit card. It identifies several things, like the payment network, the bank that issued the card and the cardholder.

The number on your card is different from your credit card 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 Long Is a Credit Card Number?

A typical credit card number is 15 or 16 digits long. But you may see some as short as eight digits and as long as 19 digits. 

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.

The Meaning of Credit Card Numbers

While they might seem random, each digit on your credit card is important for making purchases. Some individual 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 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.

First Number: Industry Identifier

Take a look at the first digit on a credit card. This digit will tell you two things: The payment network and the industry associated with the card. If the first digit is a 3, the payment network is American Express. Visas start with 4, Mastercards typically with 2 or 5 and Discovers with 6. 

Besides the payment network, the first digit identifies which industry the card is associated with. This digit is the Major Industry Identifier (MII):

  • 1 and 2 belong to cards associated with air travel and financial services.
  • 2-6 are typically used for everyday financial and banking uses.
  • 7 is for the petroleum industry.
  • 8 is for health care and telecommunications.
  • 9 is open for use by the government and is basically the “other” category. 

Identification Numbers

The next five to seven digits form the rest of the Bank Identification Number. In most cases, by combining the first through the sixth or eighth digits, you can figure out who 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 and used to make sure the card number is valid. 

Virtual Card Numbers 

One way to help keep your credit card account more secure is by using virtual card numbers. 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. 

Capital One virtual card numbers are possible thanks to Eno, your Capital One assistant. To use virtual card numbers, add the Eno browser extension and register your Capital One credit card. Eno will then generate a unique virtual card number for you when it’s time to pay. 


Learn more about Capital One’s response to COVID-19 and resources available to customers. For information about COVID-19, head over to the Centers for Disease Control and Prevention

Government and private relief efforts vary by location and may have changed since this article was published. Consult a financial adviser or the relevant government agencies and private lenders for the most current information.

We hope you found this helpful. Our content is not intended to provide legal, investment or financial advice or to indicate that a particular Capital One product or service is available or right for you. For specific advice about your unique circumstances, consider talking with a qualified professional.

Your CreditWise score is calculated using the TransUnion® VantageScore® 3.0 model, which is one of many credit scoring models. It may not be the same model your lender uses, but it is an accurate measure of your credit health. The availability of the CreditWise tool depends on our ability to obtain your credit history from TransUnion. Some monitoring and alerts may not be available to you if the information you enter at enrollment does not match the information in your credit file at (or you do not have a file at) one or more consumer reporting agencies.

Eno looks out for free trials from select merchants. Eno is learning all the time and may not catch everything, including some free trials, subscriptions, renewals, and spending activity. Push, email, and SMS notifications must be enabled to be received. Eno service outages may occur. Capital One customers are responsible for regularly checking their account statements. Web access is needed to use mobile banking. Check with your service provider for details on specific fees and charges. 

Texting with Eno means you agree to chat about your account over SMS and receive recurring messages. Message and data rates may apply. Mobile phone carrier fees for text messages may apply.

Some or all Eno features may not be available to all Capital One customers, depending on the types of accounts held. For example, certain bank accounts are not eligible to text with Eno, and Eno email notifications, app notifications and virtual card numbers from Eno may not be available for certain credit cards.

The Eno browser extension for virtual card numbers is only available in certain web browsers, and enrollment is required. Virtual card numbers are not available for debit cards and some credit cards. 

The EMVCo Contactless Indicator mark, consisting of four graduating arcs, is a trademark owned by and used with permission of EMVCo, LLC.

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