ISBNs 101: How Many Do You Need for Different Formats? (Paperback, Hardcover, Audiobook, eBook)
Publishing a book in 2025? One of the most confusing questions new authors face is:
“How many ISBNs do I actually need?”
Good news — the answer becomes simple once you understand one key rule:
Every format and edition of your book requires its own unique ISBN.
Buy ISBNs InstantlyWhat an ISBN Really Does (and Why You Need One)
An ISBN (International Standard Book Number) is the 13-digit identifier used by:
- Amazon
- Libraries
- Bookstores
- Distributors & wholesalers
- IngramSpark
- B&N Press
- KDP (if not relying on a free ASIN-only listing)
It’s not “just a barcode.” It’s the official identity of your book across the global publishing ecosystem.
If you want full distribution rights and maximum reach, you should own your ISBN.
Get Your ISBN NowThe Simple Rule: One ISBN Per Format
Here’s the quick breakdown:
- Paperback → 1 ISBN
- Hardcover → 1 ISBN
- eBook → 1 ISBN
- Audiobook → 1 ISBN
- Large Print → 1 ISBN
- Revised Edition → 1 ISBN
If the format changes → the ISBN must change.
If the edition changes → the ISBN must change.
For most authors, this means at least two ISBNs (Paperback + eBook).
Buy ISBN BundlesFormat-by-Format Breakdown
1. Paperback — Requires 1 ISBN
Paperback editions are treated as standalone products. Changes in:
- Binding
- Trim size
- Dimensions
- Page count
…make paperbacks distinct editions, requiring their own ISBN.
Buy a Paperback ISBN2. Hardcover — Requires 1 ISBN
Hardcovers differ from paperbacks because of:
- Different binding
- Different production cost
- Different audience expectations
You cannot reuse a paperback ISBN for a hardcover.
Get Hardcover ISBN3. eBook — Requires 1 ISBN
Amazon’s ASIN is not an ISBN.
If you want your eBook listed in:
- Apple Books
- Google Play Books
- Kobo
- Libraries
- Global retailers
…you must have a real ISBN.
Buy eBook ISBN4. Audiobook — Requires 1 ISBN
Audiobooks carry their own metadata and distribution systems. Platforms like:
- Audible
- ACX
- Findaway Voices
- Spotify Audiobooks
…recommend or require a unique audiobook ISBN.
Audiobook ISBN5. Large Print — Requires 1 ISBN
Large print editions serve accessibility markets and are considered separate editions.
Large Print ISBN6. Revised Editions — Requires 1 ISBN
If you publish a new edition with:
- New chapters
- Updated statistics
- New content structure
- “2nd Edition” or “Revised Edition” labeling
…you need a new ISBN. Minor spelling fixes or formatting adjustments do not require a new one.
Order ISBNs for Future EditionsExamples: Real Publishing Scenarios
Scenario A: Amazon KDP Only
Publishing:
- Paperback
- eBook
You need: 2 ISBNs
Get 2 ISBNsScenario B: Full Distribution
Publishing:
- Paperback
- Hardcover
- eBook
- Audiobook
You need: 4 ISBNs
Get 4 ISBNsScenario C: Accessibility + New Edition
Publishing:
- Paperback
- Hardcover
- eBook
- Audiobook
- Large Print
- Revised Edition
You need: 6 ISBNs
Order 6 ISBNsHow Many ISBNs Should You Buy Now?
Use this chart to plan ahead:
- eBook only → 1 ISBN
- Paperback + eBook → 2 ISBNs
- Paperback + Hardcover + eBook → 3 ISBNs
- Add Audiobook → 4 ISBNs
- Add Large Print → 5 ISBNs
- Expect revisions → 10 ISBN bundle
Most authors end up needing 3–5 ISBNs per book lifecycle.
Buy ISBNs at UPCs.comFinal Thoughts
ISBNs are a small detail with a huge impact on professionalism, distribution, and how your book is catalogued worldwide.
Remember:
- Every format needs its own ISBN.
- Every edition needs its own ISBN.
- Owning your ISBN creates the highest level of publishing freedom.
Ready to publish like a professional?
Get Your ISBNs Instantly