ISBN, Barcode and Labelling for Children's Books (2026)

The short answer

Every format needs its own ISBN: paperback, hardcover, ebook and audiobook each get one, while a reprint with no content change does not. In the US, ISBNs come from Bowker ($125 for one, $295 for ten), and KDP issues a free print ISBN. The barcode is the EAN-13 Bookland code made from your ISBN, placed at the bottom-right of the back cover.

ISBN prices are Bowker's US prices, not Harmony Publishing prices.

Updated October 2026 · By Harmony Publishing

One ISBN Per Format

Each distinct product form (paperback, hardcover, ebook, audiobook, large print) needs its own ISBN. The same text in paperback, hardcover and ebook means three ISBNs. A picture book sold on both KDP and IngramSpark typically needs at least two or three.

A reprint with no content change does not need a new ISBN, even with a new cover or a new price. A change of binding or format, a new edition with substantial content changes, or a new title does.

Where to Get an ISBN

US: Bowker is the only authorised agency. One ISBN is $125; a pack of ten is $295 ($29.50 each).
UK: ISBNs are issued through Nielsen.
Canada: free, through Library and Archives Canada.
Australia: Thorpe-Bowker.

Print books effectively require an ISBN: bookstores will not stock, libraries will not catalogue and distributors will not carry a book without one.

The KDP Free ISBN (and Its Limits)

KDP offers a free ISBN for print books (the imprint shows as Independently published), or you can supply your own. The free ISBN can only be used on KDP, so it cannot be used to publish elsewhere. If you own your ISBN, you can use one paperback ISBN across KDP and IngramSpark.

A Kindle ebook does not need an ISBN: KDP uses its own ASIN. Apple, Kobo and Barnes & Noble treat the ISBN as optional. An ebook does need an ISBN to enter library systems such as OverDrive and Libby.

The EAN-13 Bookland Barcode

The barcode is the machine-readable EAN-13 Bookland barcode derived from the ISBN-13. KDP generates one on your back cover if your file lacks one; if you supply your own, it must carry a valid ISBN matching your book. Ebooks need no barcode.

Barcode Placement (Bottom-Right)

Place it on the back cover, in the bottom-right corner, which is the Book Industry Study Group (BISG) standard that major retailers and distributors expect. For a rounded-corner board book, leave extra margin so the die-cut does not cut into the barcode.

Library Cataloguing (LCCN and PCN)

A Library of Congress Control Number (LCCN) can be applied for free at loc.gov/publish before publication, and it helps school and library adoption. A Pre-assigned Control Number (PCN) is similar.

ISBN for Print vs eBook, and Age Range in Your Metadata

In your metadata, retailers rely on the BISAC category you choose and the age range you state (for example Juvenile Fiction / Animals / General, ages 3 to 7), so set both when you list the book. For Harmony's ISBN service, see the ISBN page, the hub page and the packages page.

Publishing a children's book with Harmony

Harmony Publishing is a full-service self-publishing company. See how we work on children's books, then check the packages for what is included and the price.

See the packages Children's book publishing with Harmony

Frequently asked questions

Do I need an ISBN for my children's book?

For a print book, effectively yes: bookstores will not stock it, libraries will not catalogue it and distributors will not carry it without one. A Kindle ebook does not need one, because KDP uses its own ASIN.

Do I need a separate ISBN for the hardcover and the ebook?

Yes. Each format needs its own ISBN: paperback, hardcover, ebook and audiobook each get one.

Should I take the free KDP ISBN or buy my own?

The free KDP ISBN can only be used on KDP. If you own your ISBN, you can use one paperback ISBN across KDP and IngramSpark.

Where does the barcode go, and do I make it myself?

The EAN-13 Bookland barcode goes at the bottom-right of the back cover. KDP generates one if your file lacks it; if you supply your own, it must carry a valid ISBN matching your book.

What is an LCCN and does it help get my book into libraries?

A Library of Congress Control Number can be applied for free at loc.gov/publish before publication, and it helps school and library adoption.