Most authors know that when they write a book, an ISBN needs to be assigned to it. An International Standard Book Number (ISBN) is the book’s unique identification number used by distributors, bookstores, other retailers, and libraries to purchase books and track their sales.

You CANNOT have ONE ISBN for all the different versions of your ONE book.

All versions of a book need to have their own ISBN—they cannot be sold without one. If, for example, you write one book but have it in paperback, hardback, leather-bound, and spiral-bound versions, you would need to have 4 ISBNs. If you update a book and publish a Second Edition (or Third or Revised Edition), each subsequent edition must have its own ISBN.

Does this apply to an eBook version as well? YES … depending on how you plan to distribute it.

If you sell your eBook only on your website, you do not need to pay for an ISBN. However, you probably have grander plans for your eBook, hoping to see it available through various online outlets. Below is a recap of the other top places you might distribute your eBook:

ISBN Required?Is a Free ISBN provided for an eBook?If you have purchased an ISBN for your eBook:Notes:
Amazon KDPNONOHave it ready when you submit your eBooks to these places!An ASIN is assigned to be used at Amazon KDP only.
Apple BooksNONO
Barnes and Noble Press
(aka B&N Press)
KoboNONOA Kobo dummy number will be assigned to your eBook for use only at Kobo.
Draft2DigitalYESYES... Or you can provide your own ISBN.You cannot use a D2D-assigned ISBN elsewhere. Your own ISBN can be used at other locations.

Draft2Digital bought Smashwords in March 2022. You now register at Draft2Digital.
NO... But there will be wider distribution if you have one.YES... Or you can provide your own ISBNYou cannot use a Smashwords-assigned ISBN elsewhere. Your own ISBN can be used at other locations.
PublishDriveNOA PUI (PublishDrive Unique Identifier) can be assigned.
IngramSparkYESYES... BUT... IngramSpark encourages you to purchase your own ISBN.You cannot use an IngramSpark-assigned ISBN elsewhere. Your own ISBN can be used at other locations.
If you discover something different than what is shared in this table, please email to let her know!

You CANNOT use an ISBN from your paperback (or another version) for your eBook!

If you obtain an ISBN for your eBook, do so BEFORE publishing it to Amazon, Apple, and other places. You will need to enter it along with other information when you upload your EPUB. If you obtain an ISBN for your eBook later after publishing it at one of these locations, you must re-upload it as an updated version, such as Revised or Second Edition.

Bottom line … K.I.S.S. – Keep It So Simple … Save yourself the headache of figuring all this out for an eBook. Purchase your ISBNs for the eBook and any other version of the book you will want to publish. That way, you can publish and distribute them widely without having to parse through the unique identifier mire. It is an added expense but makes it easier to distribute your eBook more widely, lessens confusion, and keeps you in the driver’s seat.

BTW – There is no such thing as an eISBN. There are only ISBNs applied to all the different versions a book can be.

Do eBooks Need ISBNs?