What Do Credit Card Numbers Mean? Making Sense of Your Credit Card Number

What Do Credit Card Numbers MeanHave you ever wondered what those numbers embossed on the front of your credit card mean? Commonly referred to as your “credit card number, ” there is a lot more information packed into that number than meets the eye… If you have a credit or debit card, you might want to pull it out so you can follow along.

For starters, the first digit in the number indicates what type of card you’re dealing with. This number is always a 3, 4, 5, or 6, and can be interpreted as follows:

3 = Travel or entertainment card (e.g., Amex or Diner’s Club)
4 = Visa Card
5 = MasterCard
6 = Discover Card

Visa credit card numbers

For Visa cards, the numbers are 16 digits long. Visa has used to have 13 digit numbers, as well, but those have been mostly (completely?) migrated over to the 16 digit format.

When looking at the balance of the numbers, the 2nd through 6th digits are the bank number, and the 7th-15th numbers are your account number. The remaining digit is known as the “check digit, ” which is used to help determine whether or not the overall number is legitimate.

MasterCard credit card numbers

For MasterCard cards, the number is also 16 digits long. The first digit is always a 5 and the second digit is always between 1-5. The 2nd-3rd, 2nd-4th, 2nd-5th, or 2nd-6th digits correspond to the bank number, and the remaining digits up through the 15th are the account number. As above, the 16th digit is the check digit.

American Express card numbers

For American Express cards, the number is always 15 digits long and it always starts with 34 or 37. The 3rd and 4th digits indicate the card type (business vs. personal) and the currency. The 5th-11th digits are the account number, the 12th-14th digits are the card number associated with the account, and the 15th digit is, once again, the check digit.

As an example, my wife and I have an Amex Blue Cash Rewards account. Our card numbers start with 37, and the 12th-14th digits on our cards are different. The rest of the digits are, however, the same. As far as I’m aware, both Visa and MasterCard issue identical numbers when there are multiple cards per account.

Source: How Stuff Works, Credit Addict

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22 Responses to “What Do Credit Card Numbers Mean? Making Sense of Your Credit Card Number”

  1. Anonymous

    i think they should leave off the last 4 digits and let the ccv pick up the rest of the card number and expiration date. they get every thing they need to dupllicate another card. and if you know enough people and who doesn’t with twitter, facebook and linked-in. it is probably very easily done. this makes sense to me. they are really getting too much information.

  2. Anonymous

    Jason, the CVC code on the card is generated by a mathematical function which takes as inputs the card number, expiration date, and a separate unique-to-the-card code which is in the magstripe data but not printed on the card — I wouldn’t be surprised, actually, if that’s the same code value which allows credit card issuers to tell which card was used to make a given purchase. Since this makes the CVC, in turn, also unique to the card, it has to be regenerated every time the card is reissued, even if it’s the only visible change.

  3. Anonymous

    R E et al., I’m pretty sure the reason why multiple credit cards proper have identical numbers while multiple check/debit cards don’t is because your credit card number actually is your account number with the issuing bank, while a check card number is nothing like the number of the account it draws on. This implies that there’s a look-up table which maps between card numbers and bank account numbers, and this in turn makes it (relatively) very easy to have more than one check card number on a given deposit account; all you have to do is add another line to the look-up table.

    Bryan M, I’m guessing someone who knows that a bare credit card number, all by itself, actually isn’t good for a whole lot, especially when its length would disqualify it from use on just about every payment form on the web — in fact I’m honestly amazed it still works even at a cash register.

  4. Anonymous

    I don’t think that Visa necessarily gives the same card numbers when you have multiple cards per account. My husband and I have a joint account with our bank which gives us Visa check cards, and the last four digits on our cards are different. It could be because they’re check cards and not actual Visa credit cards, but still…

  5. Anonymous

    Visa does issue the same number for multiple cards on the same account but when it is swiped they have unique codes. We called the company about some suspicious charges and they were able to tell us which card it was per transaction. The card companies typically also keep track of online purchases, etc., per billing name with the card so unless you put the other person’s name (which is definitely plausible) they distinguish the cards that way too.

    Also, is there any reason why they would change the CCV security code with a renewal? This happened to me and it took a few online purchases to remember, I hate having to reach for my wallet when I know everything else on the card.

  6. Anonymous

    This is a great article! I would, though, briefly pick the nit that ‘Visa’ and ‘MasterCard’ don’t actually issue cards themselves; these associations instead license the use of their brands and infrastructure to companies such as Bank of America and Chase Manhattan, which hold the accounts, issue the cards, and take the heat. The bank numbers are registered with the associations, so they’ll be the same across an entire bank, within whatever set of bank numbers that bank actually owns (big ones like BofA and Chase have lots); the account number is set by the bank itself, and I doubt many of them use a common scheme — some of the digits may mean something, but you’d probably have to get a job at that bank to find out whether and what.

    Other than that, again, great article!

  7. Greg: I’ve heard rumors that the number you’re talking about has something to do with paying interest to the card issuer, but I wouldn’t know… While I use my card regularly, I’ve never paid a dime in interest. 🙂

  8. Anonymous

    What about the number on the piece of paper that came with the card? It was a two-digit number, with a decimal point and a percentage sign. What does that number mean?

    I ask because I’m an idiot consumer who buys everything on credit and thinks VISA and MasterCard are screwing me because my balance never seems to go down.

  9. Anonymous

    I’m with Mike. I don’t know why these types of articles fascinate me, but they do.

    Thanks, Nickel for the trivia.

    I’m still wondering though if the actual account number (for example, the 7th through 15th numbers for a Visa card) can be broken down further?

    I’m sick, I know.


    Len Penzo dot Com

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