ISBN or International Standard Book Number

What is an ISBN? An ISBN, or International Standard Book Number, is assigned to books sold through retailers. These numbers are usually 13 digits long and contain information such as where the book was published, the publisher, and the specific edition of a title.

Because the information about the book is built into the ISBN, each format (e.g., paperback, hardcover, MOBI, EPUB) requires its own International Standard Book Number. If you want to create a paperback, MOBI, and EPUB, you’ll need three ISBNs for the same title. That may seem like a lot, but ISBNs are used to track book sales, and that’s why having separate ISBNs for your book is so powerful.

Why and How to Get an ISBN

ISBNs in the United States are purchased through a company called Bowker. Bowker gives you the option of buying one, 10, or 100 ISBNs at a time. It might seem less expensive to only get one, but the problem with only buying one ISBN at a time is that these one-off ISBNs have a prefix that usually indicates the book has been self-published, and some distributors won’t carry books with those prefixes. And because ISBNs are used to track book sales, it becomes more difficult to sell your book without one—spending a little more now could result in a big return on investment later.

If you want to have retailers carry your book, you’ll want to purchase a block of 10—or use an ISBN from someone else, usually a company like Mill City Press. Using an ISBN from someone doesn’t necessarily mean they become your publishers, though. Even though Mill City Press is listed as the publisher on retailers’ websites, all that really means is Mill City Press purchased the ISBN—you retain all the rights.

How Mill City Press Helps

To avoid the expense of buying a pack of 10 ISBNS yourself (which costs around $300), Mill City Press supplies ISBNs for you. But we also give you the option to supply your own if you’d like to! How many you receive depends on how many formats of your book you publish—each format gets its own ISBN. And yes, they’re all included in your publishing plan.