To purchase an ISBN,

ISBN icon

International Standard Book Number

  • An international standard book number (ISBN) barcode to identify your book at stores.
  • Use at any self-publishing vendor, such as Kindle Direct, Ingram Spark or Smashwords.
  • $8 per ISBN.

The ISBN is the worldwide way to track and keep information on every book in publication. The barcode on the back of a book, when read by a laser, contains that book's ISBN. Each edition of a book has to have its own ISBN, whether paperback, hardback, or audiobook.

There is some leeway on this when it comes to ebooks, but some distributors, such as Smashwords, still require an ebook to have one. Whether or not you will need a one for your ebook depends on where you want to publish. In any case, you will definitely need one for your paperback edition.
In the United States, the only official selling agency is Bowker (in the UK it is Nielsen). However, buying a single ISBN from them can start around $250. That's a lot of money just to meet the needs of the book world's bureaucracy by having 13 little numbers. Publishers, on the other hand, can buy for less since they can buy in bulk, and services like Create Space will then resell them to authors at a reduced price. We can provide them to you for $8.