Before electronic publishing, I don’t think this was even a question that was asked. Books always seemed to have ISBN’s. But with the advent of digital books, this topic seems to create a massive amount of confusion. This is definitely one of those questions where you’ll get a different answer from everyone you ask. Let me Google that for you.
Where do I get an ISBN?
To help answer all your questions, the first and smartest thing to do is to visit www.myidentifiers.com, which is run by Bowker International – the U.S. ISBN agency. You can communicate with them directly. Our first hand experience is that they’ll send you a few documents pertaining to guidelines. You might as well get the information directly from THE official U.S. source so you have a solid comfort level with respect to this confusing issue.
We can tell you that if you publish in two or more different file formats (e.g. epub, PDF), you will need two separate ISBN’s. This came straight from a document sent to us from Bowker.
Bowker also goes on to explain that if there is a supplier (e.g. Amazon Kindle) that does not require an ISBN, you don’t need to get one yourself. Amazon has their own identification system.
You may be asking yourself, “but what exactly does getting an ISBN do for me?” One main thing that it does do is put your book in the worldwide catalog of published books, a catalog that is used by libraries. So if you want your book in a library, you have to have an ISBN.
It may be overkill but certainly the safest plan, and our advice, is to use a separate ISBN for every version of your book, regardless of whether it is a traditional book or an electronic version. Of course, that comes with a price. But luckily, ISBN’s aren’t too expensive.
What does an ISBN cost?
Currently, if you buy only 1 ISBN, it is expensive at a cost of $125. However, you can buy ISBN’s in blocks of 10 for $250, blocks of 100 for $575, and blocks of 1000 for $1,000. That block of 10 is a good deal if you feel you’ll have multiple versions of your book or even several different titles. And the nice thing is that from our experience, getting an ISBN is pretty immediate.
If you aren’t based in the United States, you can find a list of National ISBN Agencies on the International ISBN Agency website.