(This information is given freely as an opinion and not intended as legal advice. Follow at your own risk!)
An ISBN, or International Standard Book Number, is an integral component to getting your work published and available for purchase. Below are some common questions and concerns that arise.
What is an ISBN and when do I need one?
This thirteen-digit unique number is required if you want to distribute your book for retail (e.g. via shops, libraries, online retailers such as Amazon, etc). An ISBN is essentially a unique “address” that identifies the work’s publisher, title, and geographic location.
When is an ISBN required?
The short answer: if you are selling a printed book, it is mandatory. However, if you are simply printing your book as a gift or memento you do not plan on distributing for sale, you do not need an ISBN.
Do I only need one ISBN per book?
Technically, each individual version and format of your book should have a separate ISBN. If someone thinks they are ordering the hardcover version and receive an audio book, they will be (understandably) unhappy!
What about eBooks?
Ah, a tricky question! Technically, no. For example, if you use Kindle KDP and do not have an ISBN for your eBook, they will provide one for you (they just ask you do NOT use your print ISBN). Some authors still choose to purchase ISBNs for their eBooks to bolster copyright claims and increase professionalism. It also could potentially increase your book’s discoverability by libraries and bookstores. However, many find the cost prohibitively expensive with little reward.
Where can I purchase an ISBN and how much does it cost?
ISBNs can be purchased from various agencies, depending on your country. The only official United States ISBN agency is Bowker, and you can purchase ISBNs at www.myidentifiers.com. They are sold in packages that cost anywhere from $1.50 to $125 per ISBN (depending on how many you buy in bulk).
You can also purchase them from print-on-demand companies, such as CreateSpace and IngramSpark. These are generally cheaper (for example, CreateSpace offers individual ISBNs for $99), but these companies are simply acting as agents for Bowker.
Perhaps the most cost-effective method is simply using a free ISBN assigned by companies such as CreateSpace/KDP. However, authors should be aware that the company in question will hold the imprint, and maybe potentially limit one’s distribution power. If the ISBN is in your name, you have full control. Moreover, libraries and brick-and-mortar stores may refuse to carry books with ISBNs owned by self-publishing services such as CreateSpace and IngramSpark.
What do the numbers mean?
Believe it or not, it’s not just a random collection of numbers! Each section carries a piece of information, reading left to right:
Product – “978” is used to denote that the product is a book
Country – 0 and 1 are used for English-speaking countries
Publisher – the middle group indicates the publisher
Title – number group of varying length is used to represent the title
Check Digit – a mathematical variable of the first twelve numbers, which validates the number