Assign and check every ISBN
Record every edition's ISBN
Record the ISBN (International Standard Book Number) for every edition and format that has one. Don't reuse the hardcover number for a paperback, ebook, or audiobook sold as a separate product.
Authors often hire help with this: metadata or distribution.
Why it matters
Almost every record your book has, from the Amazon listing to the library catalog, is keyed to an ISBN. When you need to fix a listing, report a problem, or fill in an award entry, the first thing anyone asks for is the ISBN. An author who doesn't have the numbers to hand can't check anything.
Your part
- What you do
- Ask. Someone else normally owns it. Get an answer, then record it.
- Who normally owns it
- Publisher. Publisher assigns; self-publisher buys and assigns
- When
- Before publication and before metadata is sent to retailers, usually 6 to 9 months out (Assign and check every ISBN: twelve to six months before publication, before any listing goes live)Checked September 13, 2026 (opens in a new tab)
Your part changes with your publishing route.
How to do it
The full walkthrough
An ISBN (International Standard Book Number) identifies one specific product: this edition, in this format. Retailers, wholesalers, and libraries use it to order and list the book, so a book with four formats normally has four ISBNs.
Most editions and formats sold through the book trade need their own International Standard Book Number. Some platforms let you publish a platform-specific ebook or audiobook without buying one. If you assign an ISBN, use a different number for each separately available product format and edition that the ISBN rules treat as distinct. Publishing without one is a real choice with a real cost: the edition is harder to order and track outside the platform that issued its identifier, and you are not the publisher of record.
Every ISBN comes in two lengths. ISBN-13 is the current standard: 13 digits, starting with 978 or 979. It is what every form and retailer asks for. ISBN-10 is the older, 10-digit form of the same number, still printed on some older books and shown on Amazon beside the ISBN-13. They are the same identifier at two lengths, and one converts to the other, except that a 979 number has no ISBN-10 form.
A traditional publisher assigns ISBNs from its own block and will normally have them well before publication. A self-publisher buys them (in the United States, from Bowker) and assigns one per format.
Your job is not to assign the numbers. It is to know what they are, in both forms if both exist, keep them with the book's records, and later check what each one says about the book in the outside world.
If your publisher assigns the ISBN, the agency link above is background only; you will not use the site directly.
Common mistakes
- Assuming the ebook shares the print ISBN. It does not.
- Assuming the opposite too confidently: some platforms will publish a platform-specific ebook or audiobook without one. Decide, rather than drift into it.
- Using a free platform-supplied ISBN when you want to be listed as the publisher of record.
- Recording the ISBN-10 only. Use the 13-digit form everywhere.
Identifiers for Record every edition's ISBN
Set a status on any record and it joins this step. All book identifiers.
| My status | Identifier | Why this matters | Yours |
|---|---|---|---|
| ISBN The International Standard Book Number, printed above the barcode. Most formats sold through the book trade get their own. | Every retailer, wholesaler, and library orders and lists your book by this number, and the title, contributors, format, price, and publication date attached to it are what those systems display, so one wrong detail shows up in many places at once. Traditionally and hybrid published authors normally receive the numbers from the publisher and check what is attached to each one. If you publish the book yourself, you buy the numbers and assign them, and you are the one who decides whether your imprint or a platform is recorded as the publisher. Keep one list of every ISBN beside the edition and format it identifies so you can check listings against it. | Add your ISBN-13 |
A template for this
Book Identity SheetThe single source of truth for your book: every settled fact, from exact title and International Standard Book Numbers (ISBNs) to subject codes, descriptions, and contacts.
When to use it: Use this when the title and formats are settled, usually around nine months before publication. Keep it current for the life of the book, and copy from it every time a listing, form, pitch, or entry asks for a detail. Do not use this when a fact is still undecided. Mark it provisional rather than guessing, because everything downstream copies from here.
What done looks like
- A single list of every planned edition and format with its ISBN, kept in your Book Identity Sheet.
- The imprint or publisher name that the ISBN is registered to.
- A note of which numbers are live in retail systems and which are still planned.
Evidence. Done means someone says the work happened. Verified means you checked the confirmation, link, or public record yourself.
Ask your publisher
Copy this into an email. Replace the bracketed parts with your details.
Sources and last checked
- Official source
- Official source (opens in a new tab)
- Last checked
- September 13, 2026
- How confident we are
- Verified
Rules and deadlines change. We last checked this information on September 13, 2026. If you see something that needs updating, please tell us.