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Credit cards are easy to use almost every day without thinking about the numbers on the cards.
However, when we dial in numbers to buy something online, we may start to wonder, like, “What do all these numbers mean?” or “Why are there so many numbers?”
We have the answers here.
First, let’s talk about why there are so many numbers. Your credit card can contain up to 16 digits. A trillion is just 1 followed by 12 zeros, which would be more than enough to give every card in the world a unique number. Why then so many numbers?
The answer to this riddle is that the numbers mean different things, depending on where they match the pattern on your card. Here’s what each section of your credit card number means.
Primary Industry Identifier (MII)
The first number on your credit card indicates the type of card you have. Not the type of card, such as a balance or reward transfer, but rather the company or industry providing the card. It is known as the Primary Industry Identifier (MII). For example, if you have a Visa card, your credit card number starts with the number 4.
Here are the nine MII numbers:
1: Airlines
2: Airlines and financial
3: Travel and entertainment including American Express.
4: visa
5: Mastercard
6: Discover
7: Oil
8: Healthcare and communications
9: Government
Card Issuer Numbers
Banks use up to the next five digits to identify the company or credit card issuer. American Express indicates the type of card and currency using the numbers three and four.
Your account number
The remaining digits, except for the last digit, are your account number and apply only to you. When you receive a new credit card number—for example, when your card is lost—only these numbers and the last digit will change.
final number
The last number on your credit card is special. This is the only number that is determined by a formula called Luhn’s algorithm using the previous numbers on your card.
If you make a mistake in entering one credit card number when you enter it online, the online validator will know that you have entered an invalid credit card number, because this number will not be correct according to Luhn’s algorithm.
This is good for you, because you know right away that you should double-check the number, instead of having to find out about it later when your purchase was rejected.
CVV
There is another set of numbers on your card – CVV or card verification value.
If you have a Visa, Mastercard, or Discover card, the CVV consists of three digits and is located on the back of your card, to the right of the signature strip.
On an American Express card, the CVV consists of four digits and is located on the front of the card, just above and to the right of your credit card number.
Your CVV is intended to prove to online merchants that you do indeed have the card. Someone who stole your credit card number but not your CVV and expiration date will not be able to shop online. Be very careful who sees your physical credit card or where you enter your account number, including the expiration date and CVV.
Do not confuse your PIN or Personal Identification Number with your CVV. Your PIN is the number you use at an ATM, when you receive cash with a credit card, or when you make a personal purchase with a debit card. Never enter a PIN instead of a CVV.
bottom line
The numbers on your credit card have different meanings depending on their position in the 16-digit credit card number. The first digit is the type of card company or industry, the next five digits identify the credit card issuer, the next digits are your account number, and the last digit is determined by the Luhn algorithm. Along with a three- or four-digit CVV, these numbers make your particular credit card unique and help identify and protect you from fraudulent purchases.
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The editorial content on this page is based solely on the objective judgment of our contributors and is not based on advertising. It was not provided or ordered by credit card issuers. However, we may receive compensation when you click on links to our partners’ products.