Self Publishing Basics: How to Read an ISBN

by Joel Friedlander on September 8, 2009 · 16 comments

Some years ago I published a book that landed on the front page of the Sunday New York Times Book Review, which was quite a thrill for my wife and I, who were running our publishing company from a spare bedroom in our house.

Soon enough, the phone started to ring, and one call was from a distributor in New York.

“Hey, we’re all wondering down here, is this some guy publishing from his dining room? We have a bet.” There was plenty of snickering in the background.

“Well, you’d be wrong,” I said, “I’m in the bedroom. How can I help you?”

But their guess was pretty accurate, and one of the ways they may have known just how small a publisher we were was from the ISBN on the book in the review.

You Need ISBN to Sell in Bookstores

If you want to sell in bookstores, self-publishers know that you need to have an ISBN and bar code for your book. (ISBN stands for International Standard Book Number.)

Many self-publishers have taken to buying single ISBN numbers from RR Bowker or one of their authorized resellers, but if you are planning to publish more than one book—or more than one edition of your book—you really need to have your own ISBN numbers, which you will also acquire from Bowker.  As the Official ISBN Agency for the United States, Bowker is exclusively responsible for the assignment of the ISBN prefix to those publishers with a residence or office in the U.S.

But you can tell a lot just by looking at the ISBN on a book. And people who know how to read the ISBN gain some information about you from it as well. The traditional ISBN is a series of 10 digits, but there are actually three different numbers within those ten digits, and each has its separate meaning.

Breaking an ISBN Down

Let’s look at this 10-digit ISBN for example. It’s from my own ISBN log:


You’ll notice right away this sequence is actually divided into 4 number combinations but, as we’ll see, only three have any usefulness to us. First is the initial digit, in this case “0”:


The “0” is the “language group identifier” which here indicates English. Next is the six digit series “936385”:


This is the “publisher identifier,” and will show Marin Bookworks as the publisher on any book with this sequence. Because I’m a small publisher and only purchased 100 ISBNs from Bowker, my publisher identifier is long. Large publishers have much shorter publisher identifiers, leaving more digits available for individual books, which is the task of the third part of ISBN, in this case “40”:


This is the “title identifier,” and it’s assigned by the publisher to a particular book or a sprecific edition of a book. For instance, I might assign this ISBN to a softcover edition, and another ISBN to an ebook edition. As you can see, I can only use 100 ISBNs before I’ll have to go back to Bowker for more.


The last digit, in this case, “2” is the check digit. This digit is mathematically calculated and helps assure that the rest of the ISBN has been recorded or scanned accurately.

The 13-digit came into use in 2007. The format is the same, but it adds “978” at the beginning, and identifies the following string of numbers as an ISBN. This ISBN would become 978-0-936385-40-5 (different string of numbers generates a different check digit at the end).

Publishing Professionals Can Read ISBN Details

Book sellers, publishing professionals, and others who know how to “read” the ISBN, can tell for instance that you are publishing your first book. If your title identifier is “0” or “00” obviously you have started at the top of your ISBN logbook and just assigned the first number. If your publisher identifier is 7 digits, leaving only 1 digit for book identifiers, you are only planning to publish a few books. All these little clues from the ISBN give some insight into a publisher and their books.

For example, here is the ISBN from Orhan Pamuk’s fantastic novel, Snow published by Alfred A. Knopf:


Knopf, a very large publisher, has a publisher identifier of “375” leaving 5 digits for title identifier use, or a maximum of 100,000 different titles or editions Knopf can generate. This ISBN indicates they may have assigned 40,697 already.

Here is the ISBN from Steve Weber’s very useful book Plug Your Book:


Steve, a print-on-demand publisher, has a 7-digit publisher identifier, leaving him only 1 digit for title identifier use, meaning he will be able to generate only 10 ISBNs before he has to change his ISBN publisher identifier.

As you can see, anyone looking at these two ISBNs will immediately see that Knopf is a large publisher, and Steve is likely on his first or second book.

Sometimes when you are dealing with people who have been in the book business a long time, it pays to know the little details that are communicating information about your company that you may not even be aware of.

Resource: You can convert 10-digit ISBNs to 13-digit, or the other way around, with Bowker’s handy ISBN 10 / 13 Digit Converter.

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    { 10 comments… read them below or add one }

    Sunil McWan November 5, 2013 at 10:24 pm

    Dear Joel:
    thank you so much for this wonderful article. Thank you!
    Not only was it very informative but also beautifully constructed with very practical example.
    One question, if there are no hyfans or space in the ISBN, is it possible to determine if the publisher belongs to 2 or 3 or even 7 digits Identity Code by simply looking at ISBNs.



    elisabeth shackelford September 22, 2012 at 7:39 am

    Joel, I can’t get over how generous you and — and how prolific. How do you manage to do all that you do? Thank you for your always informative blogs.

    Thank you for the names of the copy editors you emailed me a few weeks back.

    Because of people like you and Joanna, my book is about to set sail.

    Kind regards,


    Pat August 24, 2012 at 4:12 pm

    I self-published my family history book in 1997 and had ten ISBN numbers assigned to me. I am planning to self-publish another book soon and wonder if I can use one of the other nine numbers assigned to me and how to do it.

    I also have an ASIN number, and a Library of Congress Catalogue Card Number. Is there any connection to these numbers and my new book?

    So would appreciate your advice.



    H Spencer October 15, 2011 at 9:23 pm

    Thank you for your article on ISBN’s. I’ve been interested for some time in discovering how to decipher this code and finally decided to take time to google the information and voilà, there you were. Personal continuing education, as I live and breathe, is working. Appreciate very much your contribution to it.

    H S


    Lynn April 6, 2011 at 12:13 pm

    Hello Joel,

    I just happened to read your article on ISBN. Actually I was looking for information on how to get one ASAP, because I have a little book scheduled to be printed in the next two weeks, by a friend publisher who resides overseas.

    Your information are very useful to me. I still have a question: How can I get that ISBN number for a book printed outside the USA? Besides, do I also need a Copyright sign and how fast can I get it?

    I am rushing because my brother could bring me the first load of books; that would save me the shipping cost.

    Thank you for your prompt answer.




    Joel Friedlander April 6, 2011 at 1:26 pm

    Hi Lynn, ISBNs are issued in the country in which the book will be published, and each country or region has its own ISBN agency. For ISBNs in the US only, go to

    The copyright symbol ( © ) you just add from your keyboard. For instance, on the Mac I just typed that symbol by hitting Option-G. Make sure the symbol appears in the book when it’s printed.

    You may have complications of both copyright and ISBN usage if you plan to print or publish in one country and sell in others. I suggest you look into this with the “friend publisher” you mentioned.

    Good luck!


    Wendy March 28, 2011 at 7:41 am

    Dear Joel,

    I was happy to discover your article on ISBN numbers and I read it with interest. I am publishing a book through Create Space. They say that they can get an ISBN number for me for free. Does that mean they will use one of their own? Does it make any sense for me to get my own ISBN number instead? This is my first of four books.

    By the way, your blog is terrific. I read it daily and have recommended it to others. Many thanks for educating all of us as well as you do.



    Joel Friedlander March 28, 2011 at 7:54 am

    Hi Wendy,
    You can use the ISBN that CreateSpace provides since they will give it to you for free, but CreateSpace will then be identified as the “publisher” of the book. If you are planning a series of books you might consider buying a block of 10 ISBNs. If you publish 4 print books and then make e-books out of them you will use 8 that way. The ISBNs you buy will be unique to your publishing company. Each way has benefits, but if you plan to publish regularly you’ll be better off with your own ISBNs.


    John November 7, 2010 at 4:04 pm

    Very helpful and clear, thanks!


    Joel Friedlander November 7, 2010 at 5:55 pm

    Glad you enjoyed it, John. If you explore around you’ll find lots of other articles like this one.


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