What an ISBN Is
An ISBN (International Standard Book Number) is a 13-digit unique identifier assigned to a specific book edition and format. It allows bookstores, libraries, distributors, and retailers to identify and track the book in their systems.
Governing standard: ISO 2108 – International Standard Book Number
Official reference: International ISBN Agency
Who Issues ISBNs in the United States
In the United States, ISBNs are issued by:
Bowker
Bowker operates the official registration system called MyIdentifiers.
Official registration site: