ISBNs: Why and How to Get Them
Understanding the cost, control, and complications of ISBNs before you publish
ISBNs aren’t cheap. So if you're a new indie author looking at all the costs of publishing, it’s understandable to ask, “Why not just use the free one from Amazon or Barnes & Noble?” After all, they make it easy. And if you're only releasing a single book, using a free ISBN might seem like the smart move.
But here’s the catch: when you don’t use your own ISBN, the retailer becomes the listed publisher. That decision might not seem like a big deal now, but it can limit your control, reduce your credibility, and create confusion down the road.
This guide is written for U.S.-based authors, since ISBN rules and registration differ by country.
What is an ISBN?
ISBN stands for International Standard Book Number. It’s a 13-digit number that uniquely identifies a specific edition of your book. Each format requires a separate ISBN.
That means:
Ebook = 1 ISBN
Paperback = 1 ISBN
Hardcover = 1 ISBN
Audiobook (if distributed outside Audible/ACX) = 1 ISBN
Some platforms (like Amazon KDP) do not require an ISBN for ebooks. They’ll assign an ASIN instead. But if you plan to publish wide—to Apple, Kobo, or libraries—you’ll want to use your own ISBN for consistency.
Using Free ISBNs: What You Get
Free ISBNs are available from:
Amazon KDP (paperbacks and hardcovers only, not ebooks)
Barnes & Noble Press
Draft2Digital
Kobo Writing Life
When you use a free ISBN:
The retailer assigns the number
That retailer’s name is listed as the “publisher”
You cannot reuse that ISBN anywhere else
So if you publish a paperback through Amazon with their free ISBN, you won’t be able to use that same ISBN through IngramSpark or B&N. The ISBN is tied to Amazon.
Why Free ISBNs Might Work for You
Free ISBNs are a valid choice for:
Authors publishing one format on one platform
Ebook-only authors who are exclusive to Amazon
Writers testing the waters before committing long term
They’re fast, easy, and cost nothing upfront. Just know that they come with restrictions.
Why You Should Consider Buying Your Own ISBNs
1. You’re Listed as the Publisher
Owning your ISBN means you can list your name or imprint as the official publisher. This gives you professional credibility and keeps your publishing brand consistent.
2. You Control the Metadata
ISBNs come with metadata—details about your book that get distributed to catalogs and databases. If you own the ISBN, you control:
Your book’s categories and keywords
Your publishing date
Your imprint or publishing name
How your book appears in distributor and library databases
With a free ISBN, the platform controls most of this information.
3. You Avoid Distribution Conflicts
Retailers are becoming more strict about ISBN usage. If the ISBN is tied to Amazon, and you try to use it through Draft2Digital or IngramSpark, your book might be rejected or removed.
This used to be rare, and authors would “simultaneously” upload to multiple sites using the same ISBN to avoid detection. That trick doesn’t work anymore. These platforms now verify ISBN ownership and cross-check publisher names through Bowker’s database.
Where to Buy ISBNs in the U.S.
In the United States, ISBNs are sold through Bowker at myidentifiers.com. Pricing as of 2025:
1 ISBN = $125
10 ISBNs = $295
100 ISBNs = $575
You’ll also register a publisher name (your own or a business imprint). ISBNs never expire, and you can assign them as needed.
What About Barcodes?
An ISBN is not a barcode. But you’ll need a barcode for your paperback or hardcover. Bowker lets you generate one for free if you’ve purchased the ISBN through them.
If you're using IngramSpark or KDP Print, they can also generate a barcode based on your ISBN during the setup process.
What About Audiobooks?
If you're using ACX/Audible exclusively, you don’t need an ISBN. Audible uses its own system.
If you plan to distribute audiobooks wide (through Findaway Voices or Spotify), you do need an ISBN for the audio edition.
What About Ebooks?
Amazon doesn’t require an ISBN for ebooks—they use ASINs.
However, Apple Books, Kobo, Google Play Books, and library distributors do require or recommend an ISBN.
Using your own ISBN ensures consistent metadata across platforms.
You don’t need an ISBN for both EPUB and MOBI formats. One ebook ISBN covers all digital versions of the same edition.
How Many ISBNs Do You Need?
Here’s a quick example for a single book:
Ebook (wide) = 1 ISBN
Paperback = 1 ISBN
Hardcover = 1 ISBN
Audiobook (wide) = 1 ISBN
That’s 4 ISBNs. If you add large print or a second edition later, that’s more.
Buying a single ISBN for $125 adds up fast. That’s why most authors go with the 10-pack or 100-pack. You don’t have to use them all at once—they’ll sit in your account until you need them.
Quick Tips for Managing ISBNs
Track usage: Keep a spreadsheet of which ISBN goes with which edition
Don’t reuse: Once assigned, ISBNs cannot be reused—even if the book is unpublished
Stay consistent: Make sure your publisher name, categories, and metadata match across platforms
If you’re publishing one ebook on Amazon as a passion project, a free ISBN is fine. But if you’re planning a career, want to publish in multiple formats, or distribute wide, you’ll want to own your ISBNs. They give you more control, more flexibility, and more professional reach. It’s not the most glamorous part of publishing, but it’s one of the most important.
