If you look at any commercially available book, the back cover lists the book's International Standard Book Number (ISBN) and barcode, along with the book's price. Any book that's sold anywhere in the world must have a unique ISBN.

An ISBN: What it is and why your book needs one

The ISBN system is an internationally recognized book identification system that's been in use since 1970. An ISBN is used for a variety of purposes, including inventory control; sales tracking; and order processing by booksellers, wholesalers, distributors, libraries, and universities. in January 2007, the ISBN became 13 digits long (it has been 10 digits long since 1970), divided into parts of variable length, with each part separated by a hyphen.

Some books have similar titles, or the same book may have multiple editions published over several years. To help keep track of every edition of every book that's published, each book is given a unique ISBN. The ISBN is displayed not only on the back cover, but also inside the book's interior on the copyright page and sometimes on the inside front or back cover.

The five parts of an ISBN-13 offer the following information:

  • The new prefix: This three-digit number (currently 978 or 979) identifies the book industry.
  • Group of country identifier: This section indicates the country where the book was published.
  • Publisher identifier: This part of the number is a unique code given to every individual publishing company.
  • Title identifier: This part of the ISBN is unique to every book and identifies the particular title or edition of that title.
  • Check digit: This single digit at the end of the ISBN validates the number. In some cases, this could be the capital letter 'X' (the Roman numeral for the number 10).

Publishers who want to find out more about implementing the new 13-digit ISBNs can check out the following two sources:

Download the free, 21-page eBook ISBN-13 For Dummies, Special Edition (Wiley).

Without a proper ISBN, most places that sell books won't be able to order or sell yours.

How and when to register for an ISBN

Throughout the world, there are 160 ISBN agencies; each is responsible for assigning unique ISBNs to new books published within a specific region. The U.S. ISBN Agency handles the United States, the U.S. Virgin Islands, Guam, and Puerto Rico.

It's important to understand that if you're using a POD publisher or a publisher that offers a turnkey self-publishing solution to authors, that the publisher/printer typically obtains an ISBN on your behalf. You only need to acquire your own ISBN if you plan to self-publish your book entirely by yourself and establish your own publishing company to do this.

Even if you represent a small publishing company planning to publish only one or two book titles, you still need to acquire an ISBN publishing prefix, along with a block of at least 10 ISBNs. This process takes approximately 15 business days; however, for an additional fee a Priority Processing (two-day) or an Express (one-day) service is available.

To acquire an ISBN publisher prefix and purchase a block of ISBNs, you must first complete and submit the appropriate form — Application for An ISBN Publisher Prefix — to The U.S. ISBN Agency. This process can be done in a couple of different ways:

  • Online application: Fill out your forms online and submit immediately. Online applications are free of charge.
  • Printed forms: Download the printable forms. After you've filled out the forms, send them via

Mail: R.R. Bowker, 630 Central Avenue, New Providence, NJ 07974

Fax: (908) 219-0188

E-mail: isbn-san@bowker.com

There is a one-time application submission fee of $20 for submitting paper forms.

All fees are nonrefundable and can be paid using a major credit card, check, or money order. In addition, ISBNs can't be transferred, sold, or reassigned because a portion of the 10- or 13-digit number represents the individual publishing company.

After you've submitted your application, you'll be asked for a wide range of information about your publishing company:

  • The company/publisher name
  • The company/publisher address, phone number, fax number, e-mail address, and Web site
  • The name of the Rights and Permissions Contact within the company, the person's title, and phone number. (In most cases, this person is the self-published author.)
  • The name of the ISBN Coordinator within the company, the title, and phone number. (In most cases, this person would be the self-published author.)
  • The year the company was founded and started publishing
  • The type of products produced by the company (books, videos, software, eBooks, spoken word cassettes/CDs)
  • The company's primary focus in terms of subject areas covered
  • Information about how your products are distributed

After you've obtained your ISBN publisher prefix and have assigned individual ISBNs to your upcoming books, each title can then be listed with Bowker's Books In Print, a comprehensive database and directory of all current and upcoming books. This directory is used by booksellers, libraries, schools, universities, and other institutions to search for and pre-order books and decide what books they want to carry in advance of the publication date. Check out the Web site.