Assign and check every ISBN
Check the data attached to each ISBN
Check that each ISBN (International Standard Book Number) carries the right title, subtitle, contributor names, and format in the source record, then check again at launch.
Authors often hire help with this: metadata or distribution.
Why it matters
This is where the duplicates come from. A subtitle on one ISBN and not another, or an illustrator on the hardcover record and not the ebook, produces separate and inconsistent listings that search engines and library catalogs treat as different books. Catching it at the source is far cheaper than chasing each retailer later.
Your part
- What you do
- Verify. Someone else may do it. Inspect the result yourself.
- Who normally owns it
- Publisher. Publisher or self-publisher maintains the record; author verifies at two points
- When
- About six months before publication when metadata first goes out, and again during launch week against live listings (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 International Standard Book Number (ISBN) is only a number until metadata is attached to it. The publisher (or you, if self-publishing) records a title, subtitle, contributors, and format against each number, first at the ISBN agency and then in the metadata feed that goes to retailers, wholesalers, and libraries. If the attachment is wrong at the source, the error is copied everywhere.
Get the metadata record for each ISBN, or at least those four fields, and compare them with your Book Identity Sheet. Ask the publisher for it about six months out, when feeds first go out, and again at launch, when listings are live and can be compared directly. If the number is registered to you, check the record at the ISBN agency too. If you entered the data yourself, check every platform dashboard: the most common error is a subtitle attached to the paperback ISBN but not the ebook, or a hardcover ISBN marked as paperback.
The check is mechanical: for each ISBN, four fields, two moments in time. Record what you found and what you fixed.
Common mistakes
- Checking only the primary format and assuming the others match.
- Comparing against a retail listing rather than the source record, so the source error is never fixed.
- Accepting a format label of "paperback" for a hardcover because it looked close enough.
- Doing the check once and never again, when feeds are updated many times before launch.
Identifiers for Check the data attached to each 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 | |
| Bowker MyIdentifiers The online store where United States publishers and self-publishers buy International Standard Book Numbers (ISBNs) and manage their title records. | The publisher name attached to an ISBN prefix is set when the block is bought and follows every number in that block, so it is the name recorded as your book's publisher of record. If your publisher bought the ISBNs, that account is theirs; normally you ask for each number and check that the publisher of record is the imprint you expect and that the title details are right. If you bought your own, the record is yours to keep correct, and accepting a free platform-supplied number instead lists the platform as the publisher. Record each number beside its format and confirm that the publisher name, price, and publication date match the finished book. | Nothing to record | |
| ONIX for Books ONline Information eXchange: the standard file that carries your book's details from your publisher or platform out to retailers and libraries. | If your subtitle is wrong at one retailer, that is one mistake; if it is wrong at a retailer, in a library catalog, and on Google Books, that is usually not three mistakes but one, in the feed, copied three times. It also explains why correcting it in one store often does not stick, because the next feed writes the old value back over your correction. Nobody acts on the feed directly: traditionally and hybrid published authors normally find out who owns it, which is the publisher's metadata or operations team and sometimes a separate distributor, and send corrections there, while a self-published book's feed is generated by the platform from the fields you filled in on its dashboard. Find the person or team that owns the book's feed so a correction goes to the source that can keep it fixed. | Nothing to record |
What done looks like
- For every ISBN, the title, subtitle, each contributor with role, and the format, exactly matching the Book Identity Sheet.
- The check done once when metadata first goes out and once at launch against live listings.
- Any discrepancy logged with the date reported and the date fixed.
- Ebook and audiobook records checked with the same care as print.
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.