Do You Need an ISBN for an Ebook?
Do you need an ISBN for an ebook? Usually not. See the rules for Amazon KDP, Apple Books, Kobo and Google Play, what an ISBN costs, and when buying one makes sense.
By Philip GhezelbashUsually, no. You don't need an ISBN to publish an ebook on Amazon KDP, and the other major stores let you publish through their own tools without one too. You do need an ISBN for a paperback or hardcover, and you may want one for an ebook if you plan to sell through bookstores, libraries or distributors that use ISBNs.
Here is how it works store by store, what an ISBN costs, and how to decide.
What an ISBN is
An ISBN (International Standard Book Number) is a unique identifier for a specific edition and format of a book. Bookstores, libraries and distributors use it to find and order books. It is not a copyright, it doesn't protect your work, and it isn't a barcode, although a barcode can be made from it.
Key points:
- Each format needs its own ISBN: paperback, hardcover, ebook and audiobook are separate, and an EPUB and a PDF sold separately each need their own.
- A significant new edition needs a new one. Fixing typos or changing the price doesn't.
- An ISBN identifies the publisher of record, which is whoever registered it.
Ebook ISBN rules by store
Rules change, so check each store's help pages before you publish.
| Store | Is an ISBN required for an ebook? | What happens if you skip it |
|---|---|---|
| Amazon KDP | No | KDP assigns an ASIN, Amazon's own identifier |
| Apple Books | No, when you publish through Apple's own self-service tools | Apple uses its own identifiers |
| Kobo Writing Life | No | Kobo issues its own identifier, but won't send the book to some partner stores that need an ISBN |
| Google Play Books | No, it's optional | Google assigns its own identifier (a GGKEY) |
| Through an aggregator | Depends on the aggregator | Draft2Digital offers a free ISBN (with D2D as publisher of record, usable only through D2D); IngramSpark requires one and gives US authors a free one |
| Gumroad, Etsy or your own site | No | Not applicable |
Amazon says plainly that an ISBN is optional for ebooks. KDP's help pages also note that ebooks and low-content books are the only formats where an ISBN is optional.
When you do need one
Paperbacks and hardcovers. KDP requires an ISBN for print. You can use a free one from KDP or buy your own (more below).
Selling through distributors, bookstores or libraries. Wholesale and library channels often work from ISBNs. If you want your book ordered by bookshops, you will likely need your own.
A single identifier across all stores. An ISBN you buy follows your book everywhere, while store-assigned identifiers only work inside that store.
Being listed as the publisher. If you want your own name or imprint shown as the publisher, you need an ISBN registered to you.
Free ISBN from KDP versus your own
For print books on KDP, you have two options.
| Free KDP ISBN | Your own ISBN | |
|---|---|---|
| Cost | Free | Paid in most countries (free in Canada and New Zealand) |
| Formats | Paperback and hardcover only | Any format |
| Where you can use it | Only on KDP | Anywhere |
| Publisher shown | "Independently published" | Your name or imprint |
The free ISBN is simple and fine for many authors who only plan to sell on Amazon. The catch is that it's tied to KDP, so you can't use it to publish the same print edition elsewhere, such as through IngramSpark.
If you buy your own, KDP checks that the book details you enter (title, author and imprint) match the registration, and it won't let you publish if they don't. Copy them exactly.
What an ISBN costs
In the US, ISBNs come from Bowker, the official agency, at these prices as of October 2026:
| Quantity | Price | Cost per ISBN |
|---|---|---|
| 1 | $125 | $125 |
| 10 | $295 | $29.50 |
| 100 | $575 | $5.75 |
Because each format needs its own, a block of 10 is usually better value if you plan more than one book or format. ISBNs don't expire. Prices and rules differ by country: for example, some countries issue ISBNs for free or at a much lower price, and the UK has its own agency. Look for your country's official ISBN agency before you pay a reseller. Barcodes may cost extra.
How to decide
Use this quick guide.
| Your plan | ISBN? |
|---|---|
| Kindle ebook only | Not needed |
| Ebook on several stores, using their self-service tools | Not needed |
| Ebook plus a KDP paperback, Amazon only | Free KDP ISBN for the paperback |
| Print and ebook through multiple channels or bookshops | Buy your own, likely a block of 10 |
| PDF sold on your own site, Gumroad or Etsy | Not needed |
| Want your own imprint as publisher | Buy your own |
If you're unsure and the book is your first, skip the ISBN for the ebook and revisit it when you have a reason. One exception: on Apple Books you can only add an ISBN when you first submit the book.
How to add an ISBN if you decide to
- Buy it from your country's official agency.
- Register the book details (title, author, format, publisher) so they match what you will upload.
- Put it on the copyright page of your book.
- Enter it in the store's ISBN field when you set up the book, using the same details.
- Use a different ISBN for each format, such as one for the ebook and one for the paperback.
Common questions
Do I need an ISBN to copyright my book? No. Copyright exists when you create the work. An ISBN is only an identifier. See our guide on how copyright works for AI-assisted books in Can I publish a book written by AI on Amazon?.
Can I use the same ISBN for my ebook and paperback? No. Each format needs its own.
Does an ISBN make my book sell better? Not by itself. Readers find books through store search, categories, covers and reviews, not ISBNs.
Do I need an ISBN for a PDF lead magnet? No.
What if I change my cover or price? You don't need a new ISBN for that. A new edition with significant changes does need one.
Does my EPUB need an ISBN inside the file? Not for KDP. If you have one, it's good practice to list it on the copyright page.
Where Koobe fits
Koobe doesn't assign ISBNs. It exports an EPUB 3 for stores, a digital PDF, a print interior PDF for paperbacks and a cover JPEG, and you add the ISBN details when you upload to each store. If you publish a paperback through KDP, you can choose the free ISBN or enter your own. Our guide on how to publish an ebook on Amazon KDP shows where that choice appears, and where to sell ebooks compares the other stores.
Describe your book in a sentence. Koobe plans the chapters, writes them, designs the cover and exports a PDF and EPUB. Your first book is free.
“Files were ready for KDP, which is what I actually needed. First book I’ve finished.”
The short answer, again
- Ebooks don't need an ISBN on KDP, Apple Books, Kobo or Google Play.
- Paperbacks and hardcovers do. KDP offers a free one for print, but only for use on KDP.
- Each format needs its own ISBN.
- Buy your own if you want to sell widely through distributors, keep your own imprint, or use one identifier everywhere.
- In the US, a single ISBN is $125 and a block of 10 is $295.