If you're going to self-publish and you don't have a clue about ISBNs, this post is for you.
ISBN is an acronym for International Standard Book Number. An ISBN is a 10- or 13-digit number given to every published book. Kind of like your social security number identifies certain things about you, an ISBN will identify a book's title, edition, publisher and certain physical characteristics about the book like binding and page count.
Just like the first three numbers in a social security number identify the ZIP code from which an application for a SSN was sent, the different numbers in an ISBN are identifiers that publishing nerds can "read." For more information on what the numbers mean, check the image or read The Book Designer's "Self-Publishing Basics: How to Read an ISBN."
What's the deal with 10- and 13- digit ISBNs?
On January 1, 2007, ISBNs were increased to thirteen digits for a couple of reason, but the big one is that the system was running out of numbers in certain parts of the world and adding digits was a reasonable fix.
The change meant that 10-digit numbers had to be converted to 13-digit numbers. So two new prefixes—978 and 979—were appended to the front of the old 10-digit ISBNs. And everything published January 1, 2007 or later was simply assigned a 13-digit number from the start.
Do I need an ISBN?
It's more than likely you'll need to obtain an ISBN for your work. The ISBN system started in 1970, and the numbers are used for different things like tracking sales, managing inventory, and processing book orders. Because of this, if you want to sell your book somewhere—as opposed to just printing a couple of copies to give your family as gifts—you'll need to make sure your book has an ISBN.
How can I get an ISBN assigned to my book?
You have a few options, depending on how you publish. First, you can do it yourself with Bowker. Through Bowker's services, you can buy a single ISBN or a block of ISBN numbers. Authors who know they will need more than one ISBN are typically encouraged to go ahead and buy a block of ten because of the pricing structure. Click through to the Bowker website, and you'll see why.
If you publish with a service like CreateSpace or Smashwords, you may be able to get an ISBN for free.
The major difference between these two options is that if you don't buy the ISBNs under your own publishing company's name, you will not be the publisher of record for your title. If that matters to you, buy your own ISBN. If it doesn't, feel free to consider all the options.
Are barcodes and ISBNs the same thing?
In bookstores, the ISBN is represented graphically by special barcode called the Bookland EAN Barcode. If you want to sell print copies in bookstores, you'll need to add the barcode to your work's cover.
If you don't plan to sell through bookstores, you could leave it off. In any case, it does no harm to put one on your book just in case.
Bowker also sells barcodes. They cost $25. There are free barcode generators online that might be worth a look. (If you've used a free barcode generator with success please let us know in the comments.)
Do all formats of my book need unique ISBNs?
Ah, the dreaded question. I could overcomplicate this, and tell you about situations in which you might not need an ISBN for an electronic version. Instead, I'm going to point any and all nerds and sticklers to this article for further reading. Those wanting a short, best practices kind of answer can just read on.
The simple, err-on-the-side-of-caution answer to the question is yes. Why? Well, pretend you want to list your book as a hardback, soft cover, and e-book edition on Amazon or in various e-book formats on Smashwords. The seller needs a way to uniquely identify those distinct formats and present them to consumers, and the ISBN is how it's done.
Do revisions need new ISBNs?
If you're not making any major changes to the text, no. Reprints with typo fixes and the like can be run with the original ISBN. However, new editions do need a new number. Think of those high school and college textbooks in all their numerous additions. If you're adding or removing chapters or otherwise making significant changes to the book, you'll need to obtain a new ISBN.