What Is an ISBN?

If you are researching self-publishing, you’ve probably come across something called an ISBN.

What is an ISBN? It is an acronym for International Standard Book Number. This is a 13-digit number that uniquely identifies your book worldwide. (Books issued before 2007 have a 10-digit ISBN.)

What Is It Used For?

The ISBN is mostly used by bookstores, book distributors and libraries to classify books.

Look at the back of any book and you will see this number, usually above or below the bar code. The ISBN is also embedded in the bar code.

Parts of an ISBN Number

The components of an ISBN include the following:

“978,” which stands for the book publishing industry
Publisher’s geographic location number
Publisher identifying number
Title identifying number
Check digit for validation (sometimes this is an X rather than a number)

How to Get an ISBN

ISBNs are assigned to publishers by an approved agency, which total more than 100 around the globe. In the United States, Bowker is the exclusive ISBN distributor. If you self-publish with an established firm, that company will apply for the ISBN for you and register the ISBN with Bowker’s Books in Print, a bibliographic database.

If you are self-publishing books, you can apply to get your own set of ISBNs. Here’s more information on how to get an ISBN. Numerous websites offer free software for generating a bar code.

Publishers Own the ISBN

Whoever generates the ISBN is the publisher. So even if you are self-publishing books, the ISBN will belong to the company, not to you, the author. You can set up a limited liability corporation (LLC) or other corporation to establish a publishing company. Then you can apply for your own ISBN. Once you have a publishing company, you can answer other people when they ask, “What is an ISBN?”

Here’s more about the pros and cons of self-publishing books. Our self-publishing guide also tells you more.

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