ISBNs: what they cost, and when a free one is fine
In the US, ISBNs come from Bowker: $125 for one, $295 for ten. Amazon KDP will give your paperback a free one, but it only works on KDP and lists the publisher as "Independently published." For an Amazon-only book that may be all you need. If you want your own imprint or more than one printer, buy them.
What ISBNs cost
Bowker is the official ISBN agency for publishers in the United States and its territories. These are its prices on myidentifiers.com:
| Pack | Price | Per ISBN |
|---|---|---|
| 1 ISBN | $125 | $125.00 |
| 10 ISBNs | $295 | $29.50 |
| 100 ISBNs | $575 | $5.75 |
| KDP free ISBN (paperback or hardcover) | $0 | Usable on KDP only |
Checked October 20, 2026. Bowker also sells blocks of 1,000.
Three facts from Bowker's page shape the decision: you need one ISBN for each edition and format, ISBNs never expire, and an ISBN from anyone other than the official agency "might not identify the publisher of the title accurately." Buy them from Bowker, not from a reseller.
How many you need
Count your formats. Each one gets its own number, and KDP adds that an ISBN cannot be reused across formats or for a new edition with significant changes (KDP).
- Paperback: one ISBN. Required.
- Hardcover: one more, if you publish one.
- Ebook: optional on KDP, which says ebooks and low-content books are the only formats where an ISBN is optional. Other ebook stores set their own rules.
- A revised edition later: a new ISBN if the changes are significant.
The pack math is simple. Two ISBNs bought singly cost $250; ten cost $295. If there is any chance of a hardcover, a second edition or a second book, the ten-pack is the better buy, and since ISBNs never expire the spares keep.
What a free ISBN gives up
KDP's help page lists the trade-off plainly:
| Free KDP ISBN | Your own ISBN | |
|---|---|---|
| Cost | $0 | $125, or $29.50 each in a ten-pack |
| Where it works | KDP only; "can't be used for publishing elsewhere" | Any printer or distributor |
| Publisher shown | "Independently published" | Your name or imprint |
| Formats | Paperback and hardcover | Any format |
| Registered to | Not you | You, as publisher of record |
The Alliance of Independent Authors, a nonprofit association of self-publishing authors, recommends that authors buy their own, and gives the reason: "Owning your own ISBN makes you the publisher of record, rather than the platform you've used to distribute your book" (ALLi). It also notes the practical consequence: an ISBN cannot be resold or transferred, so a book published under a platform's number cannot later move that number to your imprint.
When free is fine and when to buy
A free ISBN is reasonable if
- You will sell the paperback only through Amazon and have no plans for other printers.
- The book is mainly a gift or tool for your clients, and the imprint line on the retail page does not matter to you.
- You are publishing an ebook only through KDP, which does not require an ISBN at all.
Buy your own if
- You want the book to appear under your company or imprint name. For a business author, "Independently published" on the retail page is a small credibility cost.
- You plan to use IngramSpark as well as KDP, for bookstore and library distribution, with the same edition.
- You expect more than one format or more than one book. The ten-pack brings each number under $30.
- You want libraries and bookstores to see a publisher name they can look up. (The free Library of Congress number is a separate step; see the copyright and LCCN guide.)
Three common setups
| Plan | ISBNs needed | Cheapest way | Cost |
|---|---|---|---|
| Amazon paperback plus Kindle ebook, no imprint | 0 to buy (free KDP ISBN; ebook needs none) | Free | $0 |
| Paperback and ebook under your imprint, KDP and IngramSpark | 2 | Two singles ($250) or a ten-pack ($295) | $250 to $295 |
| Paperback, hardcover and ebook, with a second book planned | 3 now, 3 later | Ten-pack | $295 |
The cost difference is $125 to $295 against a total budget that is usually several thousand dollars. For most authors paying for professional editing, buying ISBNs is the easy call. For an author keeping total costs under $2,000, the free route is a legitimate saving.
Barcodes
A barcode is a picture of the ISBN and price that retailers scan. It is not the ISBN itself. Bowker sells barcodes at $25 each, one barcode with one ISBN for $150, and one barcode with ten ISBNs for $320 (Bowker). Bowker notes the price on a barcode cannot be changed once generated. Before you buy one, ask your printer and cover designer what they need; you may not need to buy one separately.
Bowker also sells bundles with extra services such as a copyright filing app. You do not need a bundle to register copyright: you can file directly with the US Copyright Office for $45.
Mistakes to avoid
- Buying from a reseller. You may not be listed as the publisher.
- Using one ISBN for paperback and ebook. Each format needs its own.
- Mismatched details. KDP requires the title, author and publisher you enter to match what you registered with the ISBN.
- Assuming an ISBN is copyright protection. Bowker says it conveys none.
- Taking the free one by default, then wanting your imprint later. The number cannot be moved.
The calculator lets you switch between a free ISBN, one, or a ten-pack and shows the effect on the total.
Common questions
How much is an ISBN in the US?
From Bowker, the official US ISBN agency: $125 for one, $295 for ten ($29.50 each) and $575 for 100. ISBNs never expire.
Is a free KDP ISBN bad?
Not for every book. It is free and works for a paperback or hardcover sold through KDP. But KDP says free ISBNs can only be used on KDP, and your book will list its publisher as "Independently published" rather than your name or imprint.
How many ISBNs do I need?
One for each format and edition: paperback, hardcover and ebook each need their own. KDP does not require one for ebooks. Most authors with a paperback and an ebook need one or two now, and more if they plan another book.
Does an ISBN protect my copyright?
No. Bowker says the ISBN conveys no legal or copyright protection. Registering copyright is a separate step with the US Copyright Office.
Can I transfer an ISBN to someone else?
No. The Alliance of Independent Authors notes that once issued, an ISBN cannot be resold, reassigned or transferred, and the original buyer stays the publisher of record.
Sources, checked October 20, 2026: Bowker, Buy ISBNs; Bowker, Barcodes; Amazon KDP, ISBN help; Alliance of Independent Authors, guide to ISBNs. Published by Scribe Media.