Everything You Need to Know About ISBNs

We frequently get asked questions about ISBNs—where to get them, do you need them, and why they matter. Since Bookmobile is a service provider, not a publisher, we do not purchase or supply ISBNs for our customers. It is the responsibility of the publisher to purchase and assign an ISBN for each book in their publishing schedule.

Nonetheless, this article aims to answer some frequently asked questions about ISBNs. Read on to learn more!



What is an ISBN and why do I need one?

An ISBN (International Standard Book Number) is the global standard for book identification. This is the number you see on most published books, usually on the copyright page and near the barcode on the cover.

If you are selling the book to major retailers, an ISBN is a necessity. An ISBN ensures:

  • you will be able to sell your book to major retailers.
  • your book will be easily found and purchased by retailers.
  • you will be correctly identified as the publisher of your book.
  • your book will have correct identification for the different formats of your titles.
  • you will see accurate book sales data.

Where do I purchase an ISBN?

ISBNs should be purchased through Bowker. Bowker is the official ISBN agency for the United States (and its territories). Purchasing an ISBN from another source may not accurately identify you as the publisher of the book, and this can affect your book being distributed and sold to retailers.

If I’m not selling my book to retailers, do I still need to purchase an ISBN?

No, if you don’t intend on selling your book to the trade (i.e. Amazon, Barnes & Noble, Baker and Taylor, etc.), you would not need to purchase an ISBN.

How many ISBNs do I need to purchase?

This depends on how many titles you’re publishing and in what formats. You will need one unique ISBN assigned to each format of every title you produce. For example, if I’m publishing one book both in print and as an ebook, I will need two different ISBNs assigned to the title—one for the print book and one for the ebook.

This means the best option for most publishers will be to purchase a pack of 10 ISBNs to start, since most publishers have more than one book and/or plan on publishing in different formats.

Do ISBNs ever expire?

Never! Any unused ISBNs can be registered and assigned to new titles at any point in the future.

If I’m reprinting my book and have corrections to make, do I need to assign a new ISBN to the title?

Usually no. Publishers often make corrections to their titles upon reprinting—to correct editorial mistakes, add praise copy, and/or update contact information. This is common practice and would not necessitate using a new ISBN as the core content is not changing substantially.

If I am publishing a new version of an existing book, do I need to assign a new ISBN to the new version of the book?

This is a tricky question and depends on a couple different factors. Some questions you may want to ask yourself:

  1. Is the content of the book changing substantially from the old version to the new version? If yes, a new ISBN would likely be the right choice, so that consumers know they are purchasing a revised and updated version of the book. This is a frequent scenario for nonfiction titles, such as textbooks, that get reissued after many years.
  2. Is the design of the book changing substantially, particularly the cover? If yes, you may want to assign a new ISBN to the new version so that consumers are purchasing the book in the design they want.

If you are making small changes that don’t substantially alter the content or design of the book, then you are probably safe to continue using the existing ISBN.

If the rights for my book reverted from the original publisher back to me, the author, and I want to reprint the book, do I need to register the book with a new ISBN?

Most likely yes. Remember, ISBNs are specific to each publisher. If rights for an already-published book revert back to the author, then the author would need to purchase a new set of ISBNs and register the title under their own publisher name prior to printing and distributing. In this situation, it is best to contact a copyright lawyer and/or reach out directly to Bowker for specialized help.

Do I need to buy a barcode from Bowker too?

While you do need to have a barcode on your book in order to sell it to retailers, you do not need to purchase a barcode through Bowker if you work with Bookmobile.

If you are a print-only customer, we can provide a barcode for a small fee of $25. If you are a design customer, we can provide a barcode at no additional cost.

At what point in the process do I need to supply an ISBN?

For design customers, we usually like to get an ISBN 1-2 weeks before a project is scheduled to go to print. This leaves us enough time to add the ISBN to the book and generate a barcode.

I still have questions. Who should I contact?

While we know a lot about ISBNs, we are by no means an expert on the subject. We recommend perusing the extensive FAQ section on the Bowker website and to contact them directly if you still have questions.