Whether you self-publish, hybrid publish, or publish traditionally, the International Standard Book Number (ISBN) is key—and mandatory for printed books sold to the public.
This guide will help you understand why you need an ISBN, the pros and cons of a free ISBN, and ISBN requirements for major self-publishing platforms such as Amazon Kindle Direct Publishing (KDP) and IngramSpark, among others.
We’ll also cover getting or buying ISBNs from Bowker/MyIdentifiers if you are based in the US, and from ISBN agencies for Australia, Canada, the UK, and other countries.
Understanding ISBNs
An ISBN is a unique 13-digit number that identifies a book. Think of it as a serial number or UPC code: it distinguishes your book globally and associates it with the publisher’s details.
Each physical format of a book—hardcover and paperback—requires a different ISBN. ISBN requirements for eBooks and audiobooks are dictated by the retailer or wholesaler.
An ISBN does not imply copyright protection. For copyright, authors need to contact the copyright authority for their country, such as the Library of Congress in the United States.
When does a book need an ISBN?
The need for an ISBN is dictated by the store, wholesaler, or distributor. For example, if you print a book for your family, an ISBN isn’t necessary. If you create an eBook and give it away on your website, an ISBN isn’t necessary.
Otherwise, the ISBN is essential for tracking inventory and sales through bookstores, online retailers, distributors, wholesalers, and libraries. It also aids in the management of your book’s metadata, ensuring maximum discoverability. (For more on this, read our guest post on Jane Friedman’s blog.)
Enter any 13-digit ISBN into Google and you’ll get details about a book. Those details are called a book’s metadata.
Getting a free ISBN: pros and cons
Several self-publishing platforms offer free ISBNs, including KDP, IngramSpark, Draft2Digital, and Findaway Voices. However, using a free ISBN also means that the publishing service company that provides it becomes the publisher of record, and you cannot use their ISBN with a competing service. You do not own and control this ISBN!
Advantages
- Cost-saving: free!
- Ease of use: platforms like KDP and IngramSpark provide a straightforward process to obtain a free ISBN during the title setup process.
Disadvantages
- Limited control: you are locked into using the business that gave you the free ISBN. The most important example is Amazon KDP. If you use their free ISBN, you cannot use another company to print your book.
- Publisher of record: the publishing service company, not you, will appear as the publisher of record. If you use the free Amazon ISBN, the publisher of record will be “Independently published.”
- Limited distribution: a free ISBN limits you to the distribution offered by the company that provided the ISBN. For example, you cannot enter Draft2Digital’s free ISBN in the ISBN field when selling your eBook via Google Books.
Buying your ISBNs means you own and control your own publishing imprint
When you own your ISBN, you can choose a publisher name called an imprint. This publishing imprint name is displayed to the public and listed on your copyright page.
Learn more about book imprints and how names are used.
Getting your own ISBN
Purchasing your own ISBN provides you with greater control over your book’s metadata and ensures you are the publisher of record. This can be particularly beneficial for authors planning to write multiple books under a consistent publishing imprint.
The international agency that governs ISBNs for all publishers has appointed a single agency for each country. Prices vary from free (in Canada) to $125 per ISBN in the US, and costs rapidly decrease based on the number you buy. In the US, ten ISBNs costs $295.
Begin with one of these links, depending on the country where you live.
Note: an ISBN assigned by any of the agencies below (assuming the book is in the same language) can be used to sell that book anywhere in the world. You do not need an ISBN from the country where you plan to sell your book.
- Australia
- Canada (also see our guide)
- New Zealand
- United Kingdom and Ireland
- United States (Bowker/MyIdentifiers)
If your country is not listed, you can find it in the international directory.
When to purchase an ISBN
It’s advisable to have your ISBN when designing your book cover, as the design includes the placement of the barcode, which contains the ISBN. You’ll also need the ISBN when setting up your title in your publishing account(s) such as Amazon KDP and IngramSpark.
Barcodes and ISBNs
As a general rule, all print books have a barcode. If you are using KDP or IngramSpark—which are print-on-demand (POD) printers—the barcode is printed free. All brick-and-mortar stores require a barcode. See our Learning Center article on barcodes.
The ISBN and major self-publishing services platforms
ISBN and Amazon Kindle Direct Publishing (KDP)
- Print books: use their free ISBN, or use your own. Amazon is also an authorized reseller for Bowker and you can buy a single ISBN for $99. This ISBN can be used anywhere, even with IngramSpark.
- Kindle eBooks: the ISBN is optional and not required.
ISBN and IngramSpark
- Print books and eBooks: use their free ISBN, or use your own. IngramSpark is also an authorized reseller for Bowker and you can buy a single ISBN for $85. This ISBN can be used anywhere, even with Amazon.
ISBN and Audible (audiobooks)
- An ISBN is not required.
ISBN and Findaway Voices (audiobooks)
- Use their free ISBN, or use your own.
ISBN and Apple Books
- An ISBN is not required.
ISBN and Draft2Digital
- Use their free ISBN, or use your own.
Resources and additional information
- Members of the Independent Book Publishers Association can get a 15% discount on ISBNs purchased from Bowker.
- Amazon KDP ISBN help page.
- IngramSpark ISBN help page.
- Register Your Book, second edition, by AuthorImprints founder David Wogahn.
- How to research a name for a self-publishing imprint.
- The myth of the eISBN: When eBooks need an ISBN.