By Sherry Roberts, The Roberts Group
The ISBN (International Standard Book Number) is your book’s identification number or fingerprint. It is a 13-digit number that all book databases use to track your books. ISBNs are how readers and buyers find your books. They are essential for sales to bookstores, for online sales, and for listing in databases and directories such as Books in Print.
There is some confusion, however, on what books need an ISBN. Do hardcover books need a different ISBN than a paperback? Do eBooks need ISBNs?
According to R.R. Bowker, which is the authorized seller of ISBNs in the United States, every edition and every version of your title should have a separate ISBN number. Bowker says, each of the following requires a distinct ISBN: hardcover, softcover, EPUB, MOBI, PDF, and audio version. Of course, Bowker sells ISBNs. So keep that in mind.
An ISBN is not necessary if you do not intend to place the book in stores, libraries, or with wholesalers. Although your print book must have an ISBN, it is NOT a requirement for eBooks. Online retailers such as Amazon and Barnes and Noble do not require an ISBN for eBooks. But be aware that not assigning an ISBN to your eBook may impact how, and if, that version of your book is listed in third-party databases for electronic books.
Some of your products may need a new ISBN—if you substantially change the product (this includes a title change). You do not need a new ISBN if you change the price, are just correcting typos, or are changing your cover for marketing purposes. However, if the change in cover substantially changes the product (i.e., would lead to customer complaints), then a new ISBN should be used.
For more information on ISBNs, visit here.