ISBNs for Self-Publishing Authors: What You Actually Need to Know

ISBNs cause more confusion than almost anything else in self-publishing. Authors either overthink them or ignore them entirely. Here's the straightforward version, focused on what actually matters if you're publishing in the UK.

What Is an ISBN?

An ISBN (International Standard Book Number) is a 13-digit identifier that's unique to your book. It's how bookshops, libraries, and distributors identify and order specific editions. Think of it as your book's barcode number.

Each format of your book needs its own ISBN. So your paperback, hardback, and ebook would each have a different ISBN. An audiobook needs one too if you're distributing it through traditional channels.

Where to Get One in the UK

In the UK, ISBNs are issued exclusively by Nielsen. There's no alternative provider. The pricing is straightforward: one ISBN costs £89, or you can buy ten for £164. If you're planning to publish more than one book (or more than one format), the ten-pack is obviously better value at £16.40 each versus £89.

You can buy them directly from Nielsen's ISBN agency website. The process is simple. You register, pay, and get your numbers. You then assign each ISBN to a specific book and format when you're ready to publish.

Do You Actually Need One?

It depends on where you want your book to be available.

If you're only selling on Amazon: You don't technically need an ISBN. Amazon assigns its own identifier (an ASIN) to every product on its platform, and for Kindle ebooks, the ASIN is all you need. For paperbacks through KDP (Kindle Direct Publishing), Amazon will give you a free ISBN if you don't have your own.

The catch with Amazon's free ISBN: It lists Amazon as the publisher (specifically "Independently Published"). You can't use that ISBN anywhere else. If you later want to sell through other retailers, bookshops, or library suppliers, you'd need to buy your own ISBN and essentially republish.

If you want to sell beyond Amazon: You need your own ISBN. Bookshops, libraries, wholesalers like Gardners, and other online retailers all use ISBNs to stock and order books. IngramSpark, the main print-on-demand distributor for wide distribution, requires an ISBN.

My honest advice: if there's any chance you'll want your book available beyond Amazon, buy your own ISBN from the start. It's a small cost relative to everything else involved in publishing a book, and it gives you full control and portability.

When to Get Your ISBN (The Publishing Checklist)

The ISBN is one of the last things you sort out before publishing. Here's roughly the order things should happen:

1. Finish your manuscript. Not the first draft. The version you're happy with structurally.

2. Get it professionally edited. This is where I come in. A professional edit catches the issues you can't see yourself, from plot holes and pacing problems to grammar and consistency errors. Every serious self-publishing guide puts editing before everything else, and they're right. No amount of beautiful cover design or clever marketing will save a book that hasn't been properly edited.

3. Cover design and interior formatting. Your book needs to look professional inside and out.

4. Get your ISBN. Once you know your formats (ebook, paperback, hardback), buy the right number of ISBNs and assign them.

5. Upload and publish. Whether that's KDP, IngramSpark, or both.

Common ISBN Mistakes

Using one ISBN for multiple formats. Your paperback and your ebook are different products and need different ISBNs. If you release a substantially revised edition, that technically needs a new ISBN too.

Buying ISBNs from third-party resellers. In some countries, companies resell ISBNs at a markup and list themselves as the publisher. In the UK, just buy directly from Nielsen. It's straightforward and you're listed as the publisher.

Worrying about it too early. You don't need an ISBN until you're ready to publish. Sort out the writing and editing first. I've had clients buy ISBNs before their manuscript was finished, and then change their plans (splitting one book into two, for example) and need additional numbers. Get the book right first.

The Bottom Line

If you're publishing exclusively on Amazon and you're fine with Amazon listed as publisher, you can skip the ISBN. Everyone else should buy their own from Nielsen. Ten for £164 is good value if you're serious about self-publishing.

But before you think about ISBNs, make sure your manuscript is ready. If you're looking for an experienced editor to get your book to that point, get in touch and I'll let you know what your manuscript needs and what it would cost.