ISBNs, what they are and how indie authors use them

What is an ISBN?

ISBN stands for International Standard Book Number. In simple terms, it is a unique number used to identify a specific edition and format of a book.

That last part matters. An ISBN is not just attached to the story itself. It is attached to a particular version of that book. So if you publish the same title in paperback, hardback and ebook, those are generally treated as separate products.

Think of it less like the identity of the novel and more like the identity of a specific published format of that novel.

When do you need an ISBN?

In practice, you usually need an ISBN for printed editions such as paperbacks and hardbacks. Whether you need one for an ebook depends on the platform you are using and how much control you want over your publishing setup.

The key thing is this: if you are releasing your book in more than one format, do not assume one ISBN covers the lot. It usually does not.

How many ISBNs might one book need?

This catches a lot of new authors out. One title can easily use multiple ISBNs.

For example, a single novel might need:

• one ISBN for the paperback
• one ISBN for the hardback
• one ISBN for a wide-distribution ebook edition

So even if you are only publishing one book, you may want more than one ISBN available from the start. Buy too few and you can end up going back for more sooner than expected, which is mildly annoying at best and a complete faff at worst.

Buying ISBNs

In the UK, authors normally buy ISBNs from the official national ISBN agency. Other countries have their own agencies and systems.

What matters most is buying them from the correct official source for your country, rather than from some random middleman trying to look useful while charging extra for the privilege.

If you are planning more than one format, or more than one book, it often makes sense to buy a block rather than a single ISBN. That gives you flexibility later and avoids having to redo the whole mental calculation every time you add a new edition.

The prices above were correct at the time of publication, however you can find current pricing and order your ISBNs on the NielsenIQ BookData website.

Registering each ISBN properly

Buying an ISBN is only part of the job. You also need to register it correctly against the right book format and metadata.

Although you can buy the ISBNs within seconds, it takes quite a lot longer to be able to actually register them. To do this you have to wait for an account to be set up on the NelisenIQ Title Editor. Now it appears that this account creation is performed manually, and takes approximately two weeks to come through, so you will need to keep this in mind. That said you do not need to do this part until you have your book files ready for submission to your chosen platforms.

That normally includes details such as:

• title and subtitle
• author or pen name
• format and binding type
• publication date
• price
• publisher name or imprint
• the page count for the book
• the number of images, if any, and what type
• the physical dimensions of the book

This is worth doing carefully. Metadata errors can create confusion later, especially once books begin appearing across retailers, databases and library systems.

In other words, this is not the glamorous part of publishing, but it is absolutely one of the bits that benefits from getting it right first time. Don't worry if you do make a mistake though, you can edit this data once it's live on the system. obviously it's better to get it right first time.

Do Amazon and KDP give you an ISBN?

For some formats, Amazon can provide an identifier or allow publication without you using your own purchased ISBN. That can be convenient, especially when starting out as it's a free service.

The trade-off is control. Using platform-provided identifiers can tie that edition more closely to the platform that issued it. If you want a cleaner, more independent publishing setup, owning your own ISBNs is often the better route.

Convenience is nice. Control is nicer. It just depends how seriously you are treating the book and how far you plan to take it.

Common mistakes to avoid

My view as an indie author

ISBNs are one of those things that seem intimidating before you start, then turn out to be mostly admin once you understand the rules. They are not exciting, but they do matter.

I chose to purchase a block of 10 ISBNs. You're almost certainly going to need more than one, however in heindsight I wish I'd bought a block of 100. If you're going to write more than 2 or 3 books then it's the cheapest option over time.

For my first book I used up 4 ISBNs:

• 1 for the eBook. Initially I thought I would use multiple distribution platforms, so it made sense. However after a few months I settled on KDP and Kindle Select which gives you access to Kindle Unlimited
• 1 for the Amazon KDP paperback. For my second book I'm not doing this due to the way Amazon groups editions of my book
• 1 for my IngramSpark paperback, or what I call Bookshop Edition
• 1 for my IngramSpark hardback, or what I call my Collector's Edition
• I didn't use one for the audiobook. I found out i didn't need to so I didn't

For indie authors, the real question is less “what is an ISBN?” and more “how many formats am I realistically going to publish, and how much control do I want over them?”

Answer that properly and the ISBN decision becomes much simpler.