books · Publishing · resources · writing

ISBN: What It Is and Why a Book Needs One

Book publishing isn’t just about finding great pieces of writing and bringing them out into the world. Sometimes it is about the nitty-gritty. This means that at some point, an author or publisher has to think about ISBNs.

Implemented in 1970, ISBN stands for International Standard Book Number. It is a unique number assigned to each format of a book and allows books to be tracked and sold. These numbers are also transformed into a barcode that is readable by various types of scanners. Though books published before 2007 have a 10 digit long ISBN, more recent publications have a 13 digit one. I believe this is simply because people started publishing too many books to keep up. The International Organization for Standardization (ISO) oversees and maintains the ISBN system. (As you might guess from the name, the group is filled with very detail oriented folks.)

ISBN Explanation.PNG

Though ISBN numbers are unreadable to most of the population, they aren’t random at all. Rather, each number plays a vital role. The 13 digit ISBN is broken out into 5 parts as illustrated above (978-81-7525-766-5). These sections are as follows:

1. EAN – These numbers, the ‘prefix’ of the ISBN, draw from the GS1 country code list. The ‘978’ listed in the example references ‘Bookland’, a neutral code that can identify books regardless of country of origin. The bulk of books that  work with start with these three digits.

2. Group – Because one set of country codes wasn’t enough, ISO had to use a second one as well. Group number can either reference a publisher or country group. The 81 marks this particular group as affiliated with India.

3. Publisher – The next set of digits references a specific publisher. In this case, the 7525 is tied to Parragon.

4. Title – And now we have finally reached the numbers that tie this ISBN to a specific title. It only took us 9 digits to get there.

5. Check Digit – The last number in the ISBN is a simple error detection digit. It doesn’t mean anything by itself, but it allows technology to assess whether or not other errors were made in the ISBN

How ISBNs are assigned varies by country. For the sake of brevity, I’ll be referring to the US’s system, but some of the principles may apply to other nations as well. Publishers typically pay a fee to a registration agency. (Though lucky folks up in Canada can register their ISBNs for free!) For the US, that group is Bowker. Self-publishers do, however, have other options for acquiring ISBNs. CreateSpace and Kindle Direct Publishing (KDP) both have options to freely assign ISBNs to books, and in most cases, I suggest indie authors use them. (Amazon appears to have affiliated with Bowker to make this happen successfully.) If an author wants to sell his or her book outside of the CreateSpace platform, they will have to pay an extra fee for a universal ISBN. If an author ever changes publishers for a book or creates a new edition of that work, a new ISBN will also need to be assigned.

And now I’ve shared more information than anyone ever wanted to know about ISBNs. Not everyone needs to remember all of these details, but if you are an indie author, it is a good idea to know what an ISBN is and why it matters.

For those of you who have already published, I’d love to know what ISBN option you to chose. I have only small ambitions, so when the time is right, I’ll probably go with the default CreateSpace and KDP ones, but there are some good arguments to be made for the other avenues.


—     —     —


Image Attribution: Sakurambo, ISBN Barcode Details, 2007,


30 thoughts on “ISBN: What It Is and Why a Book Needs One

    1. Batch numbers are certainly one way to go about it if you know that you are going to be publishing many books. Out of curiosity, do you remember whether or not Bowker does discounts for batch purchases?


  1. I don’t plan to self-pub (because I’d be such a uber fail at it), but this is fascinating information! I scan a lot of my books with my phone now to add to my Goodreads list and it’s cool knowing what I’m scanning. Granted, I’ll never remember any of the information, but hey! Random fun facts are cool, too! ^.^ Thanks for sharing!


Leave a Reply

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s