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ISBN

Listing & discoverability

Also called: International Standard Book Number

The global identifier for a print book edition. KDP will assign one free, or you can supply your own — the difference is who is listed as publisher.

Every distinct print edition needs its own ISBN. Paperback and hardcover are different editions; a second edition with substantive changes is a different edition; a reprint with a typo fixed is not. Ebooks do not require one on KDP.

KDP offers a free ISBN, and the catch is not quality but attribution: a KDP-assigned ISBN lists Amazon's imprint as the publisher of record and can only be used for KDP printing. Buying your own ISBN from your country's agency makes you the publisher of record and lets you use the same number with other print services.

For most authors selling only on Amazon, the free ISBN is fine. It becomes a genuine constraint if you plan to print the same edition elsewhere, or if the publisher-of-record line matters for how the book is perceived.

SmartKDP is not affiliated with, endorsed by, or sponsored by Amazon. Amazon, Kindle, and Kindle Direct Publishing are trademarks of Amazon.com, Inc. or its affiliates.

Related terms

  • ASIN

    The ten-character identifier Amazon assigns to every product in its catalog, including every book. It appears in the product URL and is how most Amazon tools refer to a title.

  • Expanded Distribution

    An opt-in channel that makes a paperback available to bookstores, libraries, and other online retailers. It pays a flat 40% of list price instead of the standard rate.

  • Low-content book

    A book made mostly of repeating or generated page structures rather than prose — journals, planners, logbooks, and similar fill-in interiors.