ISBNs are required for all print books. Each ISBN has a 10-digit and a 13-digit version. These are not separate numbers. ISBNs were originally only 10 digits long, but a few years back, the international ISBN registries realized that more ISBN numbers would be needed, so the system was switched to 13-digit numbers. However, some organizations are still in the process of switching over, so it's best to put both the 10-digit and 13-digit versions of the ISBN on the copyright page. (If you’re going to list only one, list the 13-digit version, since the 10-digit versions will eventually be discontinued.)
Where and how you obtain an ISBN depends on the country you live in and the POD printer you've selected. Some countries provide free ISBNs to their citizens. Others do not. Below are the instructions for publishers based in the US and UK. If you are based in another country, see the "Other Countries" section below.
If you're using IngramSpark, you must provide your own ISBN. If you're using KDP Paperback, you have other options, as explained below.
NOTE: You do NOT need to buy barcodes from Bowker if you are using KDP Paperback publishing or IngramSpark. KDP will generate the barcode for you and add it to your cover during the publication process. IngramSpark will generate the barcode for you and add it to the cover template that your designer should use.
Deciding Whether to Buy ISBNs and How Many ISBNs to Buy
If you're not sure how many ISBNs to buy, be aware that ISBNs are also useful for ebooks. ISBNs are optional for ebooks; however, if you want to use an aggregator such as Smashwords or Draft2Digital to get your books into smaller vendors or libraries, it will need an ISBN number. Smashwords and Draft2Digital will provide an ISBN for you, free of charge, but Smashwords or Draft2Digital will be listed as the publisher of record with Bowker. If you publish to Kobo, your book will not be distributed to all of their distribution partners around the world unless you’ve provided an ISBN number for the ebook. If you publish to Apple, Apple will not report your sales numbers to the big lists (NYT or USA Today) unless you’ve provided an ISBN number for the ebook.
Our advice? If you’re planning to write several books and make a career of writing, buy at least a 10-pack of ISBNs through MyIdentifiers.com. That will allow you to publish 5 books in print and ebook format, and you (or whatever publishing imprint you decide on) will be listed as the publisher. You will also be able to freely move your print book to the various POD printers without having to obtain a new ISBN. However, if you want to save money or if you’re not sure you’re going to write any further books, you can certainly get by with the free ISBNs from Draft2Digital or Smashwords or the free one from KDP.
Free ISBN (KDP ONLY):
Provide your own ISBN:
Working with MyIdentifiers.com
If you are going to set up an imprint/publishing company, be sure to list that name as the Organization Name in your profile. Otherwise, just list your legal or pen name (whatever name you are going to publish under) as the Organization Name.
Once your profile is set up, you can assign the ISBNs to your books.
To assign the ISBNs, you need to go into MyIdentifiers.com, go to My Account, and then click Manage ISBNs.
For each ISBN number, make sure you fill in at least the Title and then click through to the Format & Size page, and for Medium, click Print or E-book as appropriate, and then for Format, click Paperback or Electronic Book Text as appropriate. That's all you need to do right now. You can fill out all the rest later, once you've got a final cover and the book is ready to release.
Note that the 10-digit and 13-digit versions of the ISBN number will be listed at the top of the first page under Title Details.
You have two options for obtaining an ISBN (if you are using the KDP Paperback program, you may be able to obtain a free ISBN through the program):
Provide your own ISBN:
To make your book available for order by Waterstones and other brick-and-mortar bookstores, you must register your book with Nielsen (http://www.nielsenbook.co.uk/). To register your book, click BookData for UK on the left. There's more information about BookData on this page (scroll down). It takes around five days to register your book. You may also have to make an arrangement with a warehouse to fulfill your book orders for bookstores.
If you are based outside the US or UK, you can find out where to obtain your ISBNs at the International ISBN Agency:
Direct link to the list of all national ISBN agencies: