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Meaning of Numbers On A Debit Or Credit Card

Credit-Debit-Card I was going through the articles written so far on Knowledge Hub, when I came across the one which explained the meaning of numbers at the bottom of a cheque. Reading it made me wonder if the numbers written on a credit/debit card also have some particular meaning. So I decided to pursue this topic in detail, and as I guessed, each of these digits has a specific meaning.

Note: Since VISA and MASTER Cards are the most widely available cards, I have used them for my research. But the results hold true for all card types.


Identifying Card Issuer Type

The first digit in a card represents the Major Industry Identifier and is known as MII digit. It represents the category of entity which issued your credit card. There are following types of issuers:

MII Digit

Issuer Type


ISO/TC 68 and other industry assignments




Airlines and other industry assignments


Travel and entertainment (such as American Express and Diners Club)


Banking and financial (Visa)


Banking and financial (MasterCard)


Merchandizing and banking (Discover)




Telecommunications and other industry assignments


National assignment

You can understand this better by taking out your card and seeing the first digit. If you own a petroleum card (such as those issued by Exxon Mobil or BP) then your card number will start with 7. If you own a debit/credit card issued by a bank then it will start with 4 or 5 (depending on whether it is a Visa card or Master card).

Identifying Card Issuer

The first six digits in a card represent the issuer and is known as Issuer Identification Number (IIN). Below is a list of popular card issuers and their corresponding code:



American Express

34xxxx, 37xxxx



Master Card


So if you have a card that starts with 51 that means it is a Master Card.
Note: During my study I observed that Maestro card starts with 50 and 62. If you know something about Maestro cards, please share it through your comments.

Mathematically speaking, there can be 10 raised to power 6 (since 6 digits are used to identify an issuer), i.e. 1 million unique card issuers !!

Finding Account Number

Starting from the seventh digit to second last digit, i.e., 7th to n-1 digit in a card represents the account number. I noticed that this account number is not the same as your bank account number. For cards issued by ICICI (whether VISA or MASTER Cards), only first five digits of the card number and the account number matched, while there was no such similarity for cards issued by HDFC bank.

Conclusion: 7th to n-1 digit in the card represents the account number. This account number is not the account number of your bank but the account number generated by the Card Issuer (such as VISA or Master Card) to uniquely identify you.

A card can have a maximum of 19 digits. So the account number can be a maximum of 12 digit number. That means each issuer can issue a maximum of 10 raised to the power 12, i.e., 1 trillion cards !!

Check Digit

The last digit on the card is known as the check digit and it determines whether it is a valid card or not.

With that we come to an end on this interesting discussion about the numbers written on a debit or credit card. The next article will be even more interesting, because there we’ll see the check digit in action. We’ll find how the check digit is used to determine if the card is valid or not. We’ll also understand the reason behind having such long card numbers. So if you have not already subscribed to Knowledge Hub, I’ll advise you to do it now, so that you don’t miss the article.

In the mean time you can read the article about the meaning of numbers written at the bottom of a cheque, and if you want to understand other banking terms then I’ll suggest you to read the article on repo, reverse repo, crr, slr and bank rate.

This article has been written after a lot of research and took a lot of time, so retweets, fb share and your feedback will be greatly appreciated.

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71 Responses to Meaning of Numbers On A Debit Or Credit Card

  1. Karthik Nellutla July 23, 2010 at 10:31 am #

    Amazing job Anshul. Sometime back I wondered what the digits mean but I never cared much to read thru and get the meaning. Thank you very much for your info.
    Keep going 🙂

  2. Anshul July 23, 2010 at 10:36 am #

    Thanks Karthik. You have always been a source of motivation, thanks for that 🙂

  3. Website Hosting July 24, 2010 at 7:53 am #

    Wow…its so interesting information..The major credit card companies operate on a standardized system for assigning credit card numbers. The first digit in the series will always be a 3, 4, 5 or 6. This number designates the type of card you have. For instance, a 3 means it's a travel and entertainment card, such as American Express or Diners Club. A 4 is Visa and Visa-branded debit cards, cash cards; a 5 is MasterCard and MasterCard-branded debit cards, cash cards; and 6 is Discover.

  4. slow computer fix July 25, 2010 at 2:29 am #

    thats useful info thanks.

  5. Repointing mortar July 25, 2010 at 9:28 am #

    thansk ashul for your informative post, at least if you know what the numbers mean it can help you falling victim to fraud

  6. Antique Dolls July 26, 2010 at 7:18 pm #

    Wow. Hats down to you for coming up with this article. Great resources. The algorithm behind these credit cards are not pretty complicated after all.

  7. Denver Hotels July 26, 2010 at 11:22 pm #

    Hey Anshul, you have done a great job.I was really unknown about this thing.

  8. juicy couture July 27, 2010 at 9:56 am #

    Grateful post,Highly recommend.

  9. Forex Trading July 27, 2010 at 9:20 am #

    Hi this is cool post and useful information. I guess that this also applies to debit cards are well as credit cards?

  10. chess online July 27, 2010 at 11:51 am #

    Interesting facts… but the most important thing is what amount of money do you have in the account ;))

  11. Nicola July 27, 2010 at 11:30 pm #

    Wonderful post Anshul. I'm always wondered to myself what the digits mean. Thank for sharing this useful info.

  12. Janet July 28, 2010 at 12:39 am #

    Thanks for sharing this great post. It’s very enlightening. I absolutely love to read informative stuff particularly financial matters.. Looking forward to find out more and acquire further knowledge from here! Cheers!

  13. Inventory Control July 28, 2010 at 8:02 am #

    Nice post, very informative.. I just applied for my very first credit card last week, now I know what those numbers mean. Thanks for this informative post.

  14. Lutz July 28, 2010 at 8:20 am #

    Now I know what does it mean on all the digits that appear on my card….you know, this is what I really love about blogs, b;logs are informative and there is a lot of discoveries on taking time with all of this…

  15. Vijay July 30, 2010 at 6:04 am #

    Hey Anshul what a nice job you have done….keep sharing such stuffs…

  16. rockya220 July 30, 2010 at 8:21 am #

    It’s very enlightening. I absolutely love to read informative stuff particularly financial matters

  17. instant win July 30, 2010 at 5:56 pm #

    I feel like a dummy. I never knew those numbers on a debit/credit card meant anything. This why I love the internet. I'm always learning new things.

  18. Coil cord July 31, 2010 at 9:56 am #

    Now, my mind is clear and free from confusion about account number. Thanks a lot for the well written explanation.

  19. marya August 1, 2010 at 2:22 pm #

    The major credit card companies operate on a standardized system for assigning credit card numbers.

  20. Sathish August 1, 2010 at 4:42 pm #

    Really interesting facts and a new niche mate. Thanks for providing the details.

  21. pradaoutlet August 2, 2010 at 9:03 am #


  22. Anshul August 2, 2010 at 9:16 am #

    Hope you have subscribed to our newsletter. We cover interesting financial information from time to time. For now you can check out Meaning of numbers at the bottom of a Cheque

  23. Anshul August 2, 2010 at 9:18 am #

    Yeah that is true. But do not believe everything that you see on internet. Because there are many blogs which spread information without double checking their authenticity and such information are generally wrong. Take a look at Hoax Mails to see what I mean.

  24. milton August 2, 2010 at 7:43 am #

    wow…what useful information to me……….really nice post…..thanks for this post…

  25. Anshul August 2, 2010 at 9:08 am #

    Thanks for sharing your knowledge. This is how the cards are numbered basically. 🙂

  26. Anshul August 2, 2010 at 9:09 am #

    Yeah that is right. For instance if someone asks you your credit card number over telephone when you are buying something online, you should not give the complete number.

  27. Anshul August 2, 2010 at 9:10 am #

    Thanks for the appreciation :). This is just an overview of how credit cards are numbered. But they have complicated algorithms to check for frauds. I'll be coming up with another post on this topic. Do read it.

  28. Anshul August 2, 2010 at 9:10 am #

    Glad to be of help 🙂

  29. Anshul August 2, 2010 at 9:11 am #

    Yes this applies to both debit and credit cards.

  30. Anshul August 2, 2010 at 9:11 am #

    Thanks 🙂

  31. Anshul August 2, 2010 at 9:11 am #

    Glad that you liked the post Nicola 🙂

  32. Anshul August 2, 2010 at 9:16 am #

    I am happy that you found this information useful 🙂

  33. Anshul August 2, 2010 at 9:23 am #

    Thanks Vijay 🙂

  34. Anshul August 2, 2010 at 9:24 am #

    That is correct Marya. Thanks for sharing your insight 🙂

  35. Anshul August 2, 2010 at 9:25 am #

    Thanks for appreciating my efforts :). Hope to see you here more often 🙂

  36. Anshul August 2, 2010 at 9:25 am #

    Glad that you liked it 🙂

  37. Payday Lenders August 3, 2010 at 11:55 am #

    This is really very useful as more and more people are using these form of money. Your blog is really educational and has many valuable information.

  38. Jones Act Attorney August 4, 2010 at 8:34 am #

    Debit or credit cards are everywhere but there are some which is ignorant in using this form of money. Through this post, card holders are now enlightened with the facts about what they are holding. Thank you for this valuable information in which you had imparted to your readers. This post is a great source for everybody.

  39. IQ Test August 4, 2010 at 12:26 pm #

    In handling debit or any form of cards, cardholders should be not ignorant in using such cards. These cards carries lot of responsibility, therefore, cardholders should be wise and should know the essential things about those cards. This post provided valuable information in which, great ideas were imparted on us. Thank you for providing useful information.

  40. C. Davis August 6, 2010 at 10:10 pm #

    This was such great information. I have always wondered about the menaing of the numbers on credit cards and such. Knew it couldn't just be random. I am going to go and look for your posting about check #'s next.

  41. Calgary Motel August 7, 2010 at 3:59 am #

    Wow.. What an interesting facts! Sometime back, I also wonder about the numbers on my credit card. But I don't give so much time to search about it. So, thanks for the information. It answered my queries in mind.

  42. Anshul August 8, 2010 at 4:45 am #

    Thanks for appreciation 🙂 Hope to see you here more often

  43. Anshul August 8, 2010 at 4:49 am #

    You are right Jones. If only people are well aware about their cards then they can't be conned by some fraudsters. Thanks for appreciating my efforts 🙂

  44. Anshul August 8, 2010 at 4:49 am #

    Glad that you found it informative 🙂

  45. Anshul August 8, 2010 at 4:49 am #

    Hope you found that post informative too 🙂

  46. Angela August 10, 2010 at 6:58 am #

    This has been a very significant blog indeed. I've acquired a lot of helpful information about credit/debit cards that I never thought of before. Thank you for sharing such relevant topic with us.

  47. Vytas August 17, 2010 at 7:01 pm #

    Thanks for the article. It is pretty extensive. I knew just two points from what was described here.

  48. Sheila August 19, 2010 at 6:17 am #

    What an awesome blog! You've taught me significant information from this article. I appreciate you for taking the effort to extend this topic so comprehensively. I look forward to learning more on your upcoming posts. Thanks.

  49. Mercedes Parts August 24, 2010 at 5:34 pm #

    Awesome…! you provide great info man keep posting

  50. Juicy Couture Sale August 27, 2010 at 7:10 am #

    You've taught me significant information from this article. I appreciate you for taking the effort to extend this topic so comprehensively. Well done ,buddy!:)

  51. kathrine August 31, 2010 at 3:05 pm #

    waoo interesting fact about credit card i never know about it before it. i really like it.

  52. Options Trading September 2, 2010 at 10:12 am #

    I never knew about these numbers.I am much happy to know about this.I have 2 credit card of Visa now i get what does mean of these numbers.It is really informative blog.More then 70% people don't know about this which you share with us.

  53. Andres September 3, 2010 at 1:06 pm #

    I always wondered how they knew if a credit card is valid or not when you use it online. Thanks!

  54. Anshul September 7, 2010 at 9:25 am #

    It feels good to know that this article answered your queries. 🙂

  55. Anshul September 7, 2010 at 9:25 am #

    Thanks for such nice words Angela 🙂

  56. Anshul September 7, 2010 at 9:26 am #

    Glad to add to your knowledge.

  57. Anshul September 7, 2010 at 9:26 am #

    Hope to meet your expectations in upcoming posts too !

  58. Anshul September 7, 2010 at 9:26 am #

    Thx 🙂

  59. Anshul September 7, 2010 at 9:27 am #

    In the next post you'll find that out !!

  60. Calgary Web Design September 30, 2010 at 8:34 am #

    ..Amazing! Thanks for sharing this one to us. How I wish I knew this before I accidentally blocked my ATM Card (Automated Teller Machine)..i think it was just the same with the Visa card. That time I was trying to open my ATM on the internet. Unfortunately, I don't know what was the number of my ATM Card that's why I guessed that maybe the numbers that appeared on my ATM Card was the number that the computer was asking for. But I was confused because there were numbers that I thought were letters, still I continue. And after that..was a history..I blocked my ATM Card. What a funny story. Anyways, thanks again for sharing this significant facts to us. I learned!

  61. Cable design October 1, 2010 at 7:15 am #

    Credit cards are one of the best helping hand on a businessman like me. I'd been into my own small business and it became more successful because of my determination and best strategic plans. Everything should be learned in the most knowledgeable way in order for us to wise and good user just like in using credit cards and we must learn how to avail their promos and all the privileges they are offering. It's worth it. Thanks for the post.

  62. Edmonton Real Estate October 29, 2010 at 12:38 am #

    ..credit card was one of the very useful cards in the whole world. But it's funny that though we own this one we still don't have any knowledge about the numbers written on the card. Because of a hectic schedule and busy life nowadays, we really don't have any time to search an answer of some little things that bother on our minds. So it was really great that you shared your study here on the blog. It was a great fact. Informative fact ,actually! ^_^

  63. Cabinets November 26, 2010 at 8:24 am #

    ..What an interesting facts! This is why I really love to read blogs. It gives lot of significant and practical information. Here I learned that the major credit card companies operate on a standardized system for assigning credit card numbers.

  64. Shilpi July 15, 2011 at 8:34 am #

    it is so wonderful explanation………..easy to understand………..and remember…………….
    i liked it too much……………………..

  65. sandeep pareek August 18, 2011 at 6:19 pm #

    thank you !!!

  66. jane0018 August 30, 2011 at 2:47 am #

    I have been studying this blog on a on a random basis for more than a few days. Please keep up the writing.

  67. Madhavan January 24, 2012 at 10:25 pm #

    I surprised lot after reading this

  68. manjunath February 3, 2012 at 12:28 pm #

    thank you for giving information

  69. abhay tyagi July 29, 2012 at 10:30 am #

    hiii! anshul, you are just an amazing person that you r providing us that knowledge which I was lacking somewhere… keep going…

  70. poorani September 18, 2012 at 7:38 pm #

    now only i came to know about cards in detail. thank u and fantastic presentation is done by you.

  71. Bishwa Bhushan Agrawal September 19, 2012 at 3:09 pm #

    really nice job!!!!!!! i wonder how you found all these stuffs??

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