What Is an ISBN, and Do I Need One for My Book?

A self-published author is still an author nonetheless, and your book can have an ISBN just like everyone else's. These product identifiers are especially important if your goal is to maximize your book's visibility, profit from your title, and ensure that it's circulated in libraries for everyone to enjoy. 

ISBN stands for International Standard Book Number. This is a 13-digit number that is used by wholesalers, distributors, bookstores, universities, and libraries to identify your book. The pathway to assigning an ISBN to your publication is simple – you'll need to learn what an ISBN is, calculate how many you need, place your order with an agency, and add it to your book. 

In this blog post, Book1One shares the essential information about ISBNs and some useful links that can help you get one. 


Unpacking the ISBN Formula: What Do the Numbers Mean?

Think of the ISBN as your book's social security number – it identifies your publication as uniquely yours. If a reader or bookseller is specifically looking for a copy of your work, they can use this number to make sure they have the right title from the right author, especially if your title is similar to others in print.  

An ISBN is also used to recognize one edition of a title from another. So if you plan on updating your book in the future, that new edition will have its own ISBN that people and organizations can use to find the latest copy. 

Every ISBN is 13 digits long, and the numbers are divided into several parts. Each of these sections is separated by a hyphen and has a different meaning. Here is a breakdown of the current ISBN format: 

  • Group or country identifier: This part signifies a national or geographic collection of publishers. 
  • Publisher identifier: This portion indicates a specific publisher within a group. 
  • Title identifier: This section represents the publication title or the edition of a title.
  • Check digit: A single digit at the end, this numeral is used to validate the ISBN.

An ISBN also makes it easier to manage your book's metadata and ensure it's easily discovered through multiple avenues. For example, you may have heard about Bowker Books in Print. This is the primary bibliographic database for today's publishers, libraries, and retailers. Assigning an ISBN to your book doesn't automatically mean your title information is submitted to this highly valuable database – that is something you'll need to do separately once you have acquired it. 

Since many retailers require barcodes for publications, you can take this process a step further. An established ISBN can be translated into a globally recognized barcode format through Bowker Barcode Services, or you can order an ISBN with a corresponding barcode through an agency.


How Many ISBNs Do You Need?

Many self-published authors will only need to order one ISBN for their book. They are not reused and never expire, so you don't have to worry about updating them periodically in that regard. However, there are certain instances where you may need to order a fresh ISBN for what is technically the same publication. These instances include: 

  • Editions: Each edition of your book needs a unique ISBN. This is different from a reprint. If your book is reprinted to fix typos and other minor changes, it can keep its current ISBN. A new edition is considered a separate product from the original, and it typically contains more significant updates. 
  • Title changes: Modifying the title of your book also counts as a substantial amendment that would warrant a new ISBN for this version. 
  • Languages: Each time your book is published in a new language, that version will need a different ISBN. So you'll need one for the English version, one for the French version, and so on. 
  • Formats: If you're ordering your book in both paperback and hardcover binding styles, each format requires a unique ISBN. This helps ensure your reader can accurately find the one they want to buy or borrow.

If your work contains multiple volumes and each volume is available individually, ISBNs are assigned to each product. If your collection of works is only available as a set, you should order a single ISBN for the set. If both of these situations apply to your work, you'll need an ISBN for each volume, as well as another to identify the entire set. 

If your self-published books are available in a series, each book will need its own ISBN. However, serial publications are also entitled to an International Standard Series Number (ISSN). You can order this identifier through Library of Congress. 


Order Your ISBN

Just like most everything else these days, you can order an ISBN online from the comfort of your home or office. This is done through U.S. ISBN Agency or International ISBN Agency website. Pricing varies depending on how many numbers you're ordering, so it's important to factor this charge into your overall publishing budget. If you have a specific timeline in mind for your book to be published, these websites should have ISBN delivery information. Most identifiers can be acquired within approximately a week from application receipt, but expedited services may also be available. 


Adding the ISBN to Your Self-Published Book

Ideally, you should order an ISBN well before ordering printed copies of your book. That way, your final run can have everything it needs before it hits the shelves. The ISBN typically goes on the copyright page. For those of you who are copyrighting your self-published book, this page is typically located on the back of the title page and includes a host of other helpful information, such as: 

  • Edition 
  • Credits to the work 
  • Author's website 
  • Disclaimers 
  • Trademark notices
  • And other insights

If your book doesn't have a barcode, the ISBN should also go on the back cover. This means that you'll need to make sure your illustrator takes these elements into account during the design phase. In terms of printing, it's also a good idea to get to know how this works. Our process is pretty straightforward at Book1One, but other self-publishing companies may have specific requirements.  



If getting your self-published book on the shelves of local or national retailers and libraries is your primary goal, ordering an ISBN is an essential step in the self-publishing process. Simply gain insights into this product identifier, calculate the amount you'll need, order ISBN(s), and incorporate it into your book design.