An ISBN is not required to publish an eBook with Kindle Direct Publishing. Once your content is published on KDP, Amazon will assign it a 10-digit ASIN (Amazon Standard Identification Number), which is unique to the eBook, and is an identification number for the Kindle Book on Amazon.com.
If you already have an ISBN for your eBook, you'll be able to enter it during the publishing process. Do not use an ISBN from a print version of your book; eBook ISBNs must be unique to eBook versions. You can purchase an ISBN from multiple sources on the Web, including the official ISBN body
An ISBN is assigned to every published book. An ISBN identifies a book's edition, publisher, and physical properties like trim size, page count, binding type. Every 10-digit ISBN has a 13-digit EAN with a different last digit (the check digit). The EAN will be listed on your cover's barcode.
The ISBN in your paperback's files must match the book details entered during title setup.
Can KDP provide me with an ISBN?
KDP can provide you with a free ISBN to publish your paperback. We'll also automatically register your ISBN information with BooksInPrint.com®. This a global database of print books maintained by Bowker (the U.S. ISBN agency) and consulted by publishers, libraries, and booksellers. The "Publisher" field on your paperback's Amazon detail page will read "Independently published." This free ISBN can only be used on KDP for distribution to Amazon and its distributors. It cannot be used with another publisher or self-publishing service.
Can I provide my own ISBN?
You can buy your own ISBN from Bowker or through your local ISBN agency. ISBNs purchased from Bowker can be used to publish titles in any language. KDP authors can buy an ISBN at a discounted rate
from Bowker. If you use your own ISBN, KDP will check whether your book's imprint matches what's on file with Bowker. You will not be able to publish your book if there is a mismatch. If you are reprinting your book, the title, author name, and binding type must stay the same. A new edition requires a new ISBN.
Should I provide my own ISBN or use the free one from KDP?
It's important to some authors to provide their own ISBN because it allows them to choose their book's imprint of record. An imprint is a trade name that a publishing company uses to publish a work. If you use your own ISBN to publish your paperback, you'll be prompted to enter the imprint name as well. The imprint you enter must match either the imprint or publisher name that appears in Bowker (the U.S. ISBN agency).
Can I change my ISBN?
In keeping with industry standards, your ISBN cannot be changed once assigned. Your ISBN is associated with your book's trim size, title, and author name. That means the ISBN cannot be changed after publication.