What Is ISBN and Where to Get One

Getting your Trinity Audio player ready...

In 2010, Google calculated that there were 129,864,880 unique books in the world. That’s a mind-boggling number, and over a decade later, that figure has only increased. With the advent of ebooks and audiobooks, the total skyrockets even higher.

The publishing industry sees between 600,000 and one million new books published every year in the U.S. alone. A large percentage of these books are self-published, making them difficult to quantify and track.

With hundreds of millions of books in existence, how is it possible to keep them organized?

Libraries use Dewey Decimal Classification and the Library of Congress system to categorize and track their collections. Still, these systems are designed specifically for library shelves and do not attempt to keep track of every published book in the world.

Fortunately, a system has arisen to organize, classify, and identify every newly published book: the ISBN. Keep reading to discover what is ISBN and where to get one.


What Is an ISBN?

ISBN stands for International Standard Book Number. It is a code assigned to each edition of a published, printed work, not including journals and periodicals. Libraries, booksellers, publishers, internet retailers, and other book dealers use the ISBN to identify a specific edition of a book.

ISBN is useful for organizing, ordering, invoicing, tracking, and selling books. Each version of a book – hardback, paperback, second edition, ebook, audiobook, special edition, etc. – is assigned its own ISBN.

The ISBN identifies the edition, format, title, and publisher of a book. It once consisted of ten digits but now always contains 13. Any publicly available book, whether free or for sale, is assigned an ISBN.

An ISBN is convenient for searching for a specific edition of a book. While a search based on author and title will bring up every published version of a book, an ISBN search will only provide the particular edition of the book you are searching for as a result.

Where Is the ISBN Found?

You can find the ISBN on the back cover of a book above the barcode and on the book’s title page.

History of the ISBN

The formation of the ISBN began in 1965. W.H. Smith, the largest bookseller in Great Britain at the time, decided to convert to a computerized storage system. To implement this plan, the company needed a standardized numbering system for its inventory. They consulted with experts and, in 1966, created the Standard Book Numbering (SBN) system.

Soon after, the International Organization for Standardization (ISO) Technical Committee on Documentation (TC 46) began discussing the idea of adopting the SBN system W.H. Smith had created, modifying and expanding it for global use.

The ISO held a meeting in London in 1968, attended by representatives from UNESCO as well as the United States, the United Kingdom, Norway, The Netherlands, Germany, Eire, Denmark, and France. The discussion continued in 1969 at meetings in Stockholm and Berlin.

The representatives in these meetings finally agreed, and in 1970 the ISBN became an approved ISO standard. The ISBN is common in over 150 nations.

Parts of the ISBN

The ISBN has changed forms since its inception in 1970, although the basic format remains the same. The most significant change was that, in 2007, ISBNs went from ten digits to 13.

ISBN code
Photo by Markus Spiske on Unsplash

10-Digit Code

From the creation of the ISBN through the end of 2006, all ISBNs contained ten digits. These digits were separated into four sections by spaces or hyphens:

  • Group Identifier
  • Publisher Identifier
  • Title Identifier
  • Check Digit

The codes in each section provide specific relevant information about the book.

Group Identifier

The group identifier pinpoints the nation, geographical location, or language region of the book’s origin. This section of the ISBN may contain up to five digits.

Publisher Identifier

The publisher identifier recognizes the publishing house that has released the book. This section of the ISBN may contain up to seven digits.

Title Identifier

The title identifier distinguishes the specific edition of the book. This section of the ISBN may contain up to six digits. It also regulates the ISBN to exactly ten digits by adding zeros at the beginning of this section if necessary.

Check Digit

The check digit is the most complex section of the ISBN. It functions as a verification that the ISBN is valid. The check digit is always one digit or an X.

The check digit is derived from the numbers in the previous sections of the ISBN. The first number is multiplied by ten. Then each successive number is multiplied by one less than the number before it. Since there are nine digits, the final number is multiplied by two.

The products of each of these multiplications are then added together. This sum is divided by 11, and then the remainder is subtracted from 11. The result is the number found in the check digit. If the number is 10, an X replaces it to keep it to one space.

13-Digit Code

The ISBN was expanded to 13 digits in 2007 to increase the capacity of the system. All 13-digit U.S. ISBNs start with a 978 prefix, which allows the system to accommodate both ten- and 13-digit ISBNs.

The 13-digit ISBN consists of five sections:

  • Prefix Element
  • Registration Group Element
  • Registrant Element
  • Publication Element
  • Check Digit

As in the ten-digit ISBN, each section of the 13-digit ISBN provides specific, relevant information about the book’s origin.

Prefix Element

The prefix element is always three characters long and identifies the country of origin of a book. This element coordinates with the European Article Number (EAN) system, a broader product identification matrix.

Registration Group Element

Like the group identifier in a ten-digit ISBN, the registration group element pinpoints the nation, geographical location, or language region of the book’s origin. This element is always a single digit long.

Registrant Element

The registrant element identifies the publisher that has released the book; it serves the same function as the publisher identifier in the ten-digit ISBN. This section is five digits long.

Publication Element

The publication element identifies a book’s specific edition, much like the title identifier in a ten-digit ISBN. This element contains three digits.

Check Digit

The check digit section of the 13-digit ISBN serves exactly the same purpose as the check digit in the ten-digit ISBN. However, the formula for calculating the check digit in a 13-digit ISBN differs slightly from the ten-digit version.

Whereas the ten-digit check digit multiplies each successive number of the ISBN by a descending number – for instance, the first digit is multiplied by nine, the next by eight, the next by seven, and so forth – the 13-digit check digit multiplies each number by one or three alternately. So the first digit would be multiplied by one, the second by three, the third by one, the fourth by three, etc.

Other than this change, the check digit number in a 13-digit ISBN is calculated similarly to the check digit number in a ten-digit ISBN.

Who Needs an ISBN?

Since an ISBN is assigned to every published book, a sensible question to ask is, “Who needs an ISBN?” This question may seem particularly relevant to new or aspiring authors.

ISBNs are generated for and assigned to publishers. In many cases, the recipient of an ISBN is a publishing house. If any third party is publishing an author’s work, there is no need to obtain an ISBN. That responsibility lies with the publisher, not the author.

For authors who self-publish their work, on the other hand, obtaining an ISBN will be necessary. Remember that a separate ISBN is essential for each edition or version of each book. Suppose the book will be published in multiple printed formats (like hardback and paperback) or in a printed version and an electronic version. In that case, separate ISBNs will be necessary for each format. The same will be valid for any future revisions or special editions.

Where to Get an ISBN

To obtain an ISBN, a publisher must register with the relevant regional ISBN authority. There are no specific requirements to qualify as a publisher. Any individual, group, or company that intends to publish books qualifies as a publisher as far as the ISBN authorities are concerned.

In the United States, only one organization can issue ISBNs. R. R. Bowker in New Providence, NJ, is the sole ISBN authority for the U.S. and Puerto Rico. The ISBNs for all books published in the U.S. originate with Bowker.

In addition to ISBNs, Bowker offers barcodes, which are necessary to sell physical books.

Nielsen Book Services in Surrey distributes ISBNs for the United Kingdom and the Republic of Ireland. For first-time publishers, Nielsen processes standard ISBN orders in ten business days. They also offer an expedited service that takes three business days.

Cost of an ISBN

Each ISBN authority charges a set fee for ISBN distribution. The cost of an ISBN differs among national or regional ISBN authorities, so where a publisher resides and publishes its books will determine the cost of the ISBN.

In the United States, R. R. Bowker offers ISBN purchases in blocks of one, ten, or 100. A single ISBN costs $125. A block of ten ISBNs costs $295. A block of 100 ISBNs costs $575. You can also order larger blocks; the prices of these blocks are determined upon application.

In the United Kingdom and the Republic of Ireland, Nielsen Book Services offers single ISBNs and blocks of ten, 100, or 1,000. A single ISBN costs £89. A block of ten ISBNs costs £164. A block of 100 ISBNs costs £369. A block of 1,000 ISBNs costs £949.

While it is certainly cheaper to buy a single ISBN, it may be more cost-effective to purchase them in blocks. Since each book version will need a different number, a single work could easily require as many as ten ISBNs, making the block of ten a better value.

Photo by Spencer on Unsplash

Ebooks and ISBN

Ebooks are growing in popularity and can be purchased from many sources. In most cases, a seller of ebooks will require an ISBN just like a seller of print books.

While an ISBN is not technically a requirement on an ebook – or any book, for that matter – it is practically impossible to sell a book without an ISBN. All reputable sellers require ISBNs to add a book to their inventories.

There are, however, a few notable exceptions to this rule.

For instance, an ISBN is not necessary to publish a free book on the Apple iTunes iBookstore. However, if the book is not a free download, an ISBN is required.

Amazon Kindle Direct Publishing, on the other hand, does not require an ISBN even on books for sale. Amazon has its own numbering system for its inventory, so although they do recognize ISBNs, they do not require them.

ISBN and Barcodes

It is a common mistake to confuse the ISBN with the barcode on a book. While part of the barcode is derived from the ISBN, they are not the same thing.

The barcode on the back of a book is actually two barcodes side-by-side. The large barcode on the left is a black-and-white coded representation of the ISBN. It contains the same information as the ISBN in the same order.

The second barcode to the right is called an ISBN Addon5. This barcode contains extra information. That data often entails the price of the book and other information retailers use in their inventory systems.

So, Let’s Review: What Is ISBN and Where to Get One

The ISBN is an ingenious solution to the problem of organizing, categorizing, identifying, and codifying the millions of books in existence. With the ISBN system, the exact edition, publisher, and region of a book can be instantly identified.

While the ISBN format has changed over the years, it still serves the same purpose it was invented to fill in the late 60s. Get your ISBN by registering with the appropriate regional authority!

Related post: How to Write an eBook in 9 Easy Steps

Scroll to Top