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In a nutshell
There are many numbers that appear on the front and back of a credit card. The most important is the 16 digit credit card number itself, which includes the issuer identification number (IIN) and the holder’s account number.
- A credit card number typically contains 16 digits.
- The first number of a credit card often identifies the payment network linked to the card.
- Other numbers on a credit card include the CVV (security code) and expiration date.
What are credit card numbers?
A credit card number — the number you type in when you’re shopping online, for instance — is typically 15 or 16 digits long. An American Express card normally includes 15 digits, and a Discover, Mastercard or Visa card normally includes 16 digits.
Every card has a unique number, just as every person’s fingerprints are unique.
What do credit card numbers mean?
A credit card number is similar to a Social Security number or driver’s license number. Each one is unique and offers some form of identification. Aside from the credit card number, you’ll find the expiration date and the security code (CVV) on the front or back of a credit card. These numbers might appear on the front or back of a credit card.
Credit card number
Within each card number are four sets of digits representing different bits of information (although not every card follows this exact pattern). Here’s the rundown of what a credit card number consists of:
The first digit
The first digit of a card number is known as the major industry identifier. A 2 or 5 generally signifies the card payment network: Mastercard (2 or 5), American Express (3), Visa (4) and Discover (6). Meanwhile, a 1 represents an airline card and a 9 represents a government card, for example.
| First digit of credit card number | Credit card network |
|---|---|
2 or 5 | Mastercard |
3 | American Express |
4 | Visa |
6 | Discover |
| First digit of credit card number | Industrie |
|---|---|
1-2 | Air travel and financial services |
2-6 | Credit card networks |
7 | Petroleum |
8 | Health care and telecommunications |
9 | Government and “other” category |
Second through sixth digits
This five-digit string refers to which credit card company (such as Bank of America or Capital One) issued the card and further identifies which payment network the card belongs to (such as Mastercard or Visa).
Seventh through 14th or 15th digits
This group of digits identifies the cardholder’s account number. Contrary to what you might think, the account number and card number aren’t the same. Many cards have the same beginning digits, for example the major industry identifier. But the unique account number is an eight or nine digit sequence unique to the user.
Last digit
The last digit of a credit card number is what’s known as the checksum or check digit. This algorithm-based digit verifies that the credit card number is correct.
Expiration date
A credit card expiration date, which might appear on the front or back of the card, tells a cardholder when a card no longer is valid and needs to be replaced. The expiration date is normally four digits. So, the expiration date might be shown as a numerical month and year, like 10/27. In this case, you’d be unable to use the card after Oct. 31, 2027.
If you try to use a card after its expiration date, your transaction likely will be declined.
Before a card expires, the card issuer generally sends you a new card with a new expiration date. Once you receive the updated card, you may need to activate the card and change payment methods for bills, subscriptions and other ongoing transactions.
Security number or CVV
A credit card’s three-digit or four-digit security code, known as a CVV (card verification), adds a layer of security. This identifier also might be called a CSC (card security code). Normally, this code shows up on the back of a credit card.
The CVV or CSC helps prevent identity theft when you’re carrying out a transaction online or over the phone. This code helps confirm that a card being used in a transaction actually belongs to the cardholder.
Not all merchants require you to provide this code, however; and there’s no guarantee that giving the code to a merchant will stop credit card fraud. Just as you should protect a credit card number, you should not let a card’s CVV wind up in the hands (or computer) of a fraudster.
Personal identification number (PIN)
Another number that can help prevent credit card fraud is a PIN, or personal identification number. You may be more familiar with debit card PINs, as they’re used more often than credit card PINs are. Generally, you might use a credit card PIN for a transaction in another country or a cash advance withdrawal at an ATM.
A credit card PIN doesn’t appear on the card. Rather, a card issuer typically sends a card PIN by regular mail. Or you might be able to find the PIN by logging into your online account.
If you lose or forget a credit card PIN, you generally must ask for a new one to be sent by regular mail. However, you might be able to obtain a new PIN online or over the phone.
How do credit card numbers work?
In most cases, a credit card number is 15 or 16 digits long. Among other things, this number helps identify the card issuer and the cardholder.
While each card number is unique, card numbers generally stick to the same format, with a single number or group of numbers signifying the card issuer, card payment network and account number, and verifying the entire number. A certain number or numbers are assigned to credit card networks. For example, if the first digit is 4, it means the payment network for the card is Visa.
All credit card numbering follows a system developed by the nonprofit American National Standards Institute.
The AP Buyline roundup
A credit card number, often 15 or 16 digits long, is a unique number that tells a story. The number identifies the card payment network, card issuer and cardholder associated with a card. The final digit in this string validates a card number. The so-called checksum or check digit can detect whether someone has incorrectly entered a card number when they’re shopping online.
Frequently asked questions (FAQs)
Can 2 credit cards have the same last 4 digits?
Yes, two credit cards can have the same last four digits, but it’s not all that common.
What do the last 4 digits of a credit card mean?
Among the four digits at the end of a credit card number, the first three digits indicate the identity of the cardholder. The final digit is used to check whether a card is valid.
Can you tell what bank issued the card by the credit card number?
Yes. The first six digits of a credit card number identify which bank issued the card.
AP Buyline’s content is created independently of The Associated Press newsroom. Our evaluations and opinions are not influenced by our advertising relationships, but we might earn commissions from our partners’ links in this content. Learn more about our policies and terms here.