What is an ISBN?

So, I know I keep talking about purchasing ISBNs, and I’m sure if you’ve read a book, you’ve at least seen one of these things, but what – exactly – is an ISBN? This post will go into these identifiers and why they’re not only useful but essential to self-publication.

ISBN stands for international standard book number. They’re unique, commercial identifiers used for books. Each one is unique to the book and the publication format, which means that the same book published as a hardcover, softcover, and digital edition would all have different ISBNs, even if the text in the books is identical.

The ISBN was created in 1967 by the International Organization for Standardization (ISO). This group started in the mid-1920s and helps facilitate trade throughout the world by standardizing conventions between nations. ISBNs are either 10- or 13-digits long, depending on when they were issued. If it was issued before 2007, it’s 10-digits. Anything newer than that is 13-digits. The ISBN consists of multiple parts: 4 for 10-digit variants and 5 for 13-digit ones.

  1. Used only in the 13-digit ISBN, a prefix element – A GS1 element (either 978 or 979)
  2. A registration group element (language-sharing country group, individual country or territory)
  3. A registrant element
  4. A publication element
  5. A checksum

The registration group number is a 1- to 5-digit variant based on the language or the location of the country the book is published in. The registrant and publication elements are related to the publisher. When a publisher purchases an ISBN or a block of ISBNs, they’re issued a registrant number and a series of publication numbers. The ISBNs issued are then assigned to books. Once the block has been used up, the publisher may be given an entirely different registrant and publication number for their new set of ISBNs. The final number is the checksum or check digit. It’s used as a way to detect errors. It’s calculated from the other numbers in the ISBN. Wikipedia covers the calculation for both the 10- and 13-digit versions of ISBNs, if you really want to know how it’s done.

ISBNs are sold in the United States by Bowker, and they’re generally cheaper if you buy them in bulk. If you’re planning on self-publishing more than one book, I’d recommend buying a larger block, rather than getting them piecemeal, as you’ll save money overall by getting a larger block of ISBNs. One ISBN is, at the time I’m writing this, $125, while a block of ten is $295. Buying in bulk: it’s not just for toilet paper. Bowker also offers a service to get the EAN 13 barcode for your book, but there are honestly a ton of resources online where you can generate the barcode for free. Since the EAN-13 is the same numbers as the 13-digit ISBN (the only format you’re going to get if you’re publishing now), you don’t need to spend your money purchasing a barcode. Google for “EAN-13 barcode generator” and you’ll have plenty to work with.

Most places won’t let you publish your book without an ISBN or some other form of identifier.  It’s worth noting that, if you’re publishing through Amazon, they do have their own proprietary ISBN format, called an Amazon Standard Identification Number or ASIN. If you use this, you don’t have to pay for your identifier, but it’s only valid on Amazon. If you’re only planning on publishing on Amazon, that’s fine, but if you want to publish in multiple marketplaces, you really need to spend the money on an ISBN. It gives you a lot more freedom and widens your distribution channels.

ISBNs are used all over the world and are the easiest way to find books, especially specific editions. They’re rather dull if I stop and think about it, but they’re also integral to self-publishing and publishing in general. Understanding what they are and why we use them is helpful to understanding the publishing world at large.

I have decided to lessen the number of posts I write a week, so I will see you guys on Friday instead of Wednesday. I hope you guys enjoy the week, and I’ll see you soon!