International Standard Book Numbers (ISBNs) are important for self publishers. Some printers, print-on-demand publishers, and ebook vendors will offer to provide you with an ISBN, but it’s usually better to get your own. Part of the ISBN includes a “publisher number,” which is assigned to a specific publisher. Therefore, if you allow another company to provide the ISBN, then that company will be listed as the publisher of your book.
We’ll explain everything you need to know: how, where, and why to get your own block of ISBNs, and how to assign them to your print and digital books.
ISBNs are assigned by an agency in your country. They usually come in blocks of 10, 100, or 1,000, and you’ll need a separate number for each edition of your book. Even if you’re publishing just one book, be sure to get more than one number as you’ll probably produce more than one edition (for example, a softcover edition and an ebook edition). You might even have other editions, such as hardcover and audio.
For example, for Book Design Made Simple, we’ve already used four numbers for different editions:
- First edition – 978-0-9940969-0-6
- EPUB edition – 978-0-9940969-1-3
- Second edition – 978-0-9940969-2-0
- MOBI edition – 978-0-9940969-3-7
Below we’ll explain everything you need to know about:
How to get ISBNs
As mentioned earlier, ISBNs are assigned by the ISBN agency in your country. Some countries provide them for free and others require a fee.
Getting ISBNs in the United States
US publishers can purchase ISBNs from RR Bowker LLC. They are available one at a time, or in blocks of 10, 100, or 1,000. It’s best not to buy just one, as you’ll need a unique number for each edition of your book.
Getting ISBNs in Canada
ISBNs are free to Canadian publishers. Go to Library and Archives Canada ISBN, where you’ll see the steps to register explained. Once approved, you’ll receive a user ID and password by email, together with instructions for using your online account. You’ll then be able to assign a unique number from your block to each edition of your book through your online account.
Getting ISBNs outside North America
Go to the International ISBN Agency and click the “Find an agency” button. Select your country from the drop-down menu and you’ll see information there on how to obtain them.
What the numbers stand for
In North America, most retail products are marked with a UPC symbol. The corresponding bar code symbol in use outside North America is the European Article Number (EAN). Every EAN begins with a two- or three-digit prefix, which indicates the country of origin. EANs for companies registered in France, for example, might begin with the prefix 34; Australia’s prefix is 93. Since the book industry produces so many products, it has been designated as a country unto itself and has been assigned its own EAN prefix. That prefix is 978, and it signifies Bookland, that wonderful, fictitious country where all books come from. Soon the numbers with a 978 prefix will be all used up! But don’t worry, 979 is up next.
The publisher number is a unique seven-digit number assigned to your publishing company. All the books you publish will have the same country prefix, country indicator, and publisher number. The only digits that will change from book to book are the title number and check digit.
You’ll assign a unique title number to each edition of each book you publish.
Assigning ISBNs to print books
When you’ve obtained your block of ISBNs, you’ll need to assign a unique number to each edition of every book you publish. Let’s say your first book is a hardcover. That means your first number will be assigned like this:
ISBN 978-0-1234567-0–3 / BookTitle1 / Hardcover Edition
The second-last number is 0, the first digit in your block of ISBNs. This number is always assigned to the first edition (in this case the hardcover edition) of your first book. The last number is automatically calculated by an algorithm, and it’s called the “check digit.” (Sometimes the check digit is an X, so don’t worry if you get an X as the check digit in one of your ISBNs.)
Let’s say you then release a softcover edition of your book. You’ll assign the next ISBN in your block of numbers to your softcover edition:
ISBN 978-0-1234567-1–7 / BookTitle1 / Softcover Edition
The second-last number is 1, being the next digit in your block of ISBNs. And the last number is the check digit. So far so good, right?
Assigning ISBNs to ebooks
There are three main formats for ebooks: EPUB (for ereaders such as Kindle, Nook, Kobo, iBooks), MOBI (for fixed-layout Kindle books, such as comics), and PDF.
The best practice as of November 2021 is to assign a single ISBN to multiple ebook formats of a single title. Fixed-layout Kindle ebooks can still use the MOBI format, but all reflowable ebooks moving forward will be EPUBs.
We now recommend assigning one ISBN for the EPUB, MOBI, and PDF formats of a title.
Can your ebook be published without an ISBN?
Yes. If you are only publishing a Kindle edition through Amazon’s Kindle Direct Publishing, you can use their internal ASIN tracking number to track your sales instead. Or, if you are only selling ebooks from your own website, you can choose not to assign ISBNs to them.
Keep in mind that publishing ebook editions using your own ISBNs means that you’ll be listed as the publisher in the appropriate Books in Print database, and that may help readers search for your ebook online.
For more information about assigning ISBNs to ebooks, visit Bowker’s eBook FAQs and download their info PDF.
Does a reprint or second edition require a new ISBN?
You don’t need to assign a new number if you’re ordering another print run of your book with no substantial changes (just fixing a few typos, for example). If you’ve changed the cover but not the text, you can continue to use the same number.
You’ll need to assign a new number if you’ve changed the content of your book or added new material (another chapter, preface, appendix, or other content, for example). In this case the book is a new edition.
ISBNs—part of the publishing process
Getting your own ISBNs is easy to do online, and allows you to retain control of your books after they’re published. You might choose to get your books printed somewhere else down the road, or produce an updated version or second edition. When you have your own block of numbers, you’ll be in control of your books’ destiny.
Read more: Your copyright page: everything you need to know including a template to use in your book »
Read more: The saga of the second edition: learn from our experience »
And more: The ISBN tag shows all related info on our website »
Book Design Made Simple. You can do it yourself.