ISBN stands for International Standard Book Number. If you want to sell a paper book anywhere, including bookstores and other brick and mortar stores, book websites, libraries, book wholesalers, or distributors, you will need one. The ISBN is a unique 13-digit number.
Just to make things more mystifying, it corresponds to a 10-digit number. Sometimes, when registering your book on a website, you may be asked for 10-digit number as well as the 13-digit number, but luckily, you should not have to keep a record of this number, because all of the websites I have encountered automatically convert your 13-digit number to your 10-digit number. I know this may seem unnecessarily confusing; I only mention it because I have had authors ask me about this 10-digit number. For all practical purposes, you only have to worry about your 13-digit ISBN.
You will also need a barcode. Stores require the barcode so that they can easily scan their inventory at the cash register. Encoded in the barcode is the price of the book.
The ISBN identifies the publisher
This means you must be careful where you buy it. Amazon KDP (Kindle Direct Publishing) and other book websites offer ISBNs either free or at very inexpensive prices. Many first-time authors obtain their ISBN through these sites without understanding the consequences. Let me put it another way. The ISBN is part of the branding of your book. If you “brand” your book with an ISBN that identifies you as a KDP author, you lose credibility.
Why? Because KDP will publish anything by anyone who pays and uploads their material. There is no quality control. A KDP ISBN says, “I don’t know what I’m doing.”
So where should you purchase your ISBN and barcode? From bowker.com. Bowker offers a variety of “discoverability” resources for authors. I suggest every author go to Bowker’s site and browse it to see what is offered and what can be useful to you in marketing your book. An ISBN costs $125 for one book or $295 for ten books, so if you have any idea of publishing more than one book, purchase a group of ten. You must, however, purchase your barcode separately, and they cost about $50. Bowker often has specials on many of their products, so before you need your ISBN, sign up for their newsletter and start watching for specials.
Your publishing name
I strongly recommend you register your ISBNs under a different name than your own, even if you plan to publish only one book. For example, if you are writing a nonfiction book and already own a business, purchase your ISBNs under the business name. If you do not have a business, create a publishing name. Why? Again, for credibility. Your publishing company appears on all of the listings about your book, including the book itself. A book that says “written by Jane Doe and published by Jane Doe” will have less credibility than one that says “written by Jane Doe, published by Deer Park Publishing.”
This publishing name is called an “imprint.” It does not mean you are establishing a separate business. Just let me say one more time, if you have any questions about the legal or tax implications, check with your attorney or your accountant.
It is very difficult to change an ISBN without changing, at the very least, the title of your book. Understanding the implications of the ISBN will help you to make the right choices before you purchase.