Do you need an ISBN?
It depends on how you're distributing your book:
- Ebook sold only on Amazon (Kindle): No ISBN required. Amazon uses its own ASIN identifier.
- Ebook distributed to other retailers (Apple Books, Kobo, Barnes & Noble, etc.): Most require an ISBN.
- Print book sold on Amazon through KDP: Amazon will assign a free ISBN from the 979-8 range, or you can supply your own.
- Print book distributed to bookstores and libraries: You need an ISBN. Libraries require ISBNs for cataloging; bookstores and distributors like Ingram require them for ordering.
How to get an ISBN as a self-publisher
Option 1: Free from Amazon KDP (979-8)
Amazon's Kindle Direct Publishing assigns free ISBNs from the 979-8 registration group to books published through their platform. These ISBNs are assigned automatically and identify Amazon as the publisher of record in ISBN databases. The 979-8 prefix is immediately recognizable to industry insiders as a KDP-published book.
This is fine for many self-publishers, but there are trade-offs: you cannot use a KDP-assigned ISBN on a book distributed through non-Amazon channels, and the publisher of record will be listed as Amazon/KDP rather than your own imprint.
Option 2: Purchase from your national ISBN agency
In most countries, ISBNs are sold by the national ISBN agency or a designated agency. In the United States, this is Bowker (myidentifiers.com). In the UK, it's Nielsen. In Canada, ISBNs are free from Library and Archives Canada.
- US (Bowker): Single ISBN ~$125; 10 ISBNs ~$295; 100 ISBNs ~$575
- UK (Nielsen): ISBNs are sold in blocks; pricing varies
- Canada: Free (Library and Archives Canada)
- Australia: Free (Thorpe-Bowker)
When you purchase ISBNs through Bowker or your national agency, you register your own publisher name. Your books will be listed under your imprint rather than Amazon's, and you can use the ISBN across all distribution channels.
What ISBN prefix will I receive?
This depends on how many ISBNs you purchase:
- 1 ISBN: You receive a single number, not a prefix. You cannot publish additional books under the same prefix.
- 10 ISBNs: You receive a block from a shared prefix range. These are often in the 978-1 or country-specific range.
- 100 ISBNs: A dedicated publisher prefix in the 978 range with 100 numbers available.
- 1,000+ ISBNs: A shorter publisher prefix with larger capacity.
If you buy a single ISBN and want to publish more books later, you'll be buying individual numbers each time rather than building a coherent publisher prefix. Most self-publishers who plan to publish multiple titles buy at least 10 ISBNs upfront.
ISBN vs ASIN: what's the difference?
An ISBN is an internationally standardized book identifier managed by the International ISBN Agency. It's recognized by libraries, bookstores, and distributors worldwide.
An ASIN (Amazon Standard Identification Number) is Amazon's own internal identifier. It's only meaningful within Amazon's ecosystem. A book can have both an ISBN and an ASIN; ebooks sold exclusively on Kindle typically only have an ASIN.
Decoding your own ISBN
Once you have an ISBN, paste it into the decoder tool to verify it decodes correctly — confirming the registration group, publisher prefix, and check digit are all valid. This is a useful sanity check before printing barcodes or submitting your book to retailers.