In the self-publishing sphere the question of whether your book needs an ISBN pops up as frequently as questions about grammar and whether an idea has merit. My aim is to help clear up the murk and answer this question in depth. But the short answer is: it depends. 

What does ISBN stand for?

First of all, let's cover what ISBN means. The International ISBN Agency's definition goes: ‘It is an International Standard Book Number. It's a unique identifying code used all over the world by publishers, booksellers, libraries, online and offline retailers. ISNB is used in every stage of the book selling process including ordering, listing, selling and stock control.

Image credit: Barcode and ISBN of The Ruins of Hampi: Travel Guide.  Source: Wikipedia 

In a nutshell, that long string of numbers identifies your book as your book. Used by book databases throughout the world, the ISBN identifies your title and your book publisher.

Once an ISBN is assigned to a book it cannot be re-assigned. One ISBN for one book. An ISBN does not confer copyright or trademark rights on a title. It's just a number for identifying the book.

What do I need an ISBN for?

You need a different ISBN for every version and edition of your book. This includes print, e-book and audiobooks. I thought it'd be one ISBN per book; that's not the case.

But you don’t necessarily always need one. Keep reading.

How do I get an ISBN?

If you’re traditionally published through an agency, acquiring and assigning ISBNs is something you, as the author, won’t have to worry about. If you chose to self-publish, it’s a job you’ll need to add to your list.

There are two main methods of acquiring an ISBN. The first is, you buy them in single or multiple blocks from your regional ISBN agency. In some countries, ISBNs are free so be sure to check!

The second method is the ISBN is assigned to your book through the publisher or marketplace you choose to sell through. Whilst acquiring an ISBN through your marketplace, you typically won’t be allowed to reuse that ISBN anywhere else. This can lead to having a lot of ISBNs assigned to a single title across the multiple marketplaces you choose to sell it, compared to having your own ISBN which you can use on every marketplace for your single title. This can lead to a logistical nightmare of multiple listings of the same title on a global marketplace.

A further note to consider is whether you intend to build your own brand. Having a free ISBN assigned to your title lists the publisher as the marketplace which provided the ISBN. Whereas, if you choose to use publish with your own ISBN, you yourself will be listed as the publisher which can be an important brand building tool.

Here’s a quick cheat sheet:

Acquiring your own ISBN


  • You are the publisher
  • And it helps you build your publishing brand.
  • You can use the same ISBN on multiple marketplaces and
  • You retain full control.


  • You’ll have to shell out for the ISBNs yourself,
  • You’ll need to acquire a new ISBN per different edition of your book and
  • Each ISBN can only be used once.

Getting your ISBN assigned by your marketplace


  • It’s free!
  • And one less thing to worry about.


  • You cannot use assigned ISBN codes on other marketplaces.
  • Assigned ISBN may prevent your title being stocked in brick and mortar stores.
  • You are not the publisher.
  • In addition to having a different ISBN per different version and edition of your book, you’ll also have multiple ISBNs for the same title across multiple marketplaces.

Important Caveat: e-books

E-books are a grey area for ISBN assignment. Some marketplaces allow e-books to be sold without an ISBN, instead using their own identification numbers that are designed to work with their own listings. If you intend to only create e-books then for the majority of marketplaces you won't need to assign an ISBN to it, free or paid. This can affect your choice of having an ISBN in the first place.


Do you need an ISBN for your book? Yes and no. Through this article we've looked at why you need an ISBN and why you don't. If you're still unsure whether you need one or not, ask yourself these questions:

When you've answered those questions, you'll know whether you need an ISBN or not, and whether or not you need to acquire your own ISBN.

I chose to get my own ISBNs because I wanted to build my own brand and I wanted my book to have the greatest reach on multiple marketplaces. At the moment, I plan to only produce e-books and though I don't currently need to assign ISBNs, I choose to do so. This is because I'll be producing print books in the future. I need ISBNs.

Do you?

Did you enjoy this article or have questions? Why not hop over to Discord and say hi to Roger (@Sol) in person? Roger lives and works in the North of England and his debut science-fantasy novel Transient is now available on Amazon.

Cover image: KoalaParkLaundromat from Pixabay