When people write books, including ebooks, getting themselves an ISBN is often an afterthought – if they think of it at all. I thought it might be good to explain exactly what an ISBN is and why it is important.
What is an ISBN?
'ISBN' stands for 'International Standard Book Number'. It is a 'serial number' for a book: no two books, or ebooks, published anywhere in the world will have the same ISBN.
ISBNs are essential for maintaining order in book catalogues because they overcome the fact that both book titles and author names can be duplicated. ISBNs can also help avoid confusion when a book has multiple editions – by applying a unique ISBN to each edition, anyone searching for a specific edition will be able to identify it.
(A handy hint when comparing the price of books at online stores: to make sure you're comparing like with like, find the ISBN of the book you're looking for at the first store, then search on that number, rather than the title, at subsequent stores.)
Since 2007, all ISBNs are 13-digit numbers; prior to that they were made up of 10 digits. On paper books you'll usually find the ISBN represented as a barcode on the back of the book. It will also appear on the copyright page. In an ebook it should also appear on the copyright page or equivalent.
How are ISBNs issued?
While ISBNs are global in their reach, they are issued country by country. In each country, a single organisation holds responsibility for the task – sometimes a government organisation and sometimes a private organisation.
In Australia, ISBNs are issued and managed by Thorpe-Bowker, a subsidiary of US firm Bowker. Anyone – including a self-publisher – can register an ISBN via the myidentifiers.com.au website at a cost of $42. However, you'll need separate ISBNs for your printed book and your ebook, so it's usually better to buy a 'pack' of ten ISBNs for the price of two. The 'spares' are yours to keep and can be used for future publications or updated editions.
If you're in a country other than Australia, a quick web search should identify your local ISBN issuer.
Note that some self-publishing services can provide you with an ISBN (which they will previously have obtained from their local issuer). Just be wary of paying too much for this 'service' as it is often priced excessively or ridiculously overvalued in package deals. Ebook distributor Smashwords provides ISBNs for free to their clients.
Why get an ISBN?
When you apply an ISBN to your book, you are making sure it will appear in the global 'Books in Print' catalogue. This catalogue is used around the world as a 'master' catalogue by bookstores and libraries.
What this means in practice is that if someone walks into a bookstore or library requesting your book, but it isn't in stock, the outlet should still be able to track it down. Via your book's entry in the database, they will be able to work out who published the book and who distributes it. Importantly, that means they'll be able to place an order. Needless to say that in the era of the shrinking book shop, this is fairly important.
Another advantage of an ISBN is that having one on your book, along with other administrative elements, adds to the sense of it being a 'real book' – something I think is critical to self-published works.
So, before you hit the 'Go' button on your next publishing project, make sure you organise your ISBNs and make your book visible to the whole wide world.