An ISBN, or International Standard Book Number, is the 13-digit number that identifies one edition and format of a book. Bookstores, libraries and online retailers use it to order and track your book. When you self-publish, you can either use a free ISBN from a platform or buy your own. Which one makes sense depends on where you want your book to go.

What ISBNs cost in 2026

In the United States, the official ISBN agency is Bowker, which sells them through MyIdentifiers.com:

• 1 ISBN: $125
• 10 ISBNs: $295 ($29.50 each)
• 100 ISBNs: $575

ISBNs never expire, so a block of ten covers your first several books and formats.

The free option, and its catch

Amazon KDP gives you a free ISBN for a paperback or hardcover. It’s a fine choice for some books, but it comes with two limits:

1. Your book’s imprint, the publisher listed on the product page, will read “Independently published.”
2. The ISBN can only be used on KDP. If you later want the same paperback on IngramSpark for bookstores and libraries, you’ll need a different ISBN, which creates a second edition with a separate listing.

Kindle ebooks don’t need an ISBN at all; Amazon assigns its own identifier.

When a free ISBN is fine

• You only plan to sell on Amazon.
• It’s a personal project, a family keepsake, or a short run for friends and church.
• You’re testing an idea and may revise it heavily.

When to buy your own

• You want your book in bookstores or libraries through IngramSpark.
• You want your own imprint name, such as “Prairie Creek Press,” on the copyright page and retail listings.
• You plan to write more than one book, or publish in more than one format.
• You want one consistent edition, with the same ISBN on Amazon and everywhere else.

How many ISBNs does one book need?

One per format. A paperback and a hardcover need separate ISBNs. If you publish your ebook outside Amazon, it needs one too. A new edition with significant changes needs a new number; fixing a few typos does not. Most authors who publish a paperback, hardcover and ebook use three, which is why the ten-pack is the better value.

Barcodes

You don’t need to buy a barcode from Bowker for a print-on-demand book. KDP and IngramSpark both generate the barcode on your cover from your ISBN and price.

What we recommend

For a book you care about and want to see in stores, buy the ten-pack in your own name, or under an imprint name you choose. It costs less than a single round of cover revisions and keeps you in control of your book for good. When we publish your book, we buy ISBNs in your name at cost and register them for you, so you’re the publisher of record. See our publishing packages.