What is an ISBN?  

The International Standard Book Number (ISBN) is a 13-digit number that uniquely identifies books and book-like products published internationally.

ISBNs are applicable to: •printed books and pamphlets •atlases and maps   •Braille publications   •mixed media publications   •electronic publications •microforms •educational videos or movies   •microcomputer software (please refer to the guidelines extracted from ISBN Review) ISBNs are not applicable to: •newspapers and magazines •serial publications •diaries and calendars   •advertising matters   •art folders without title page and text   •sound recordings   Structure of an ISBN Every ISBN comprises 13 digits, which can be grouped into five sections: 1.Prefix Element – Adopting the Prefix Element assigned to books by the GS1, all ISBNs are currently prefixed by “978”.  When ISBNs with “978” prefix are exhausted, the new “979” prefix will be used. 2.Group Identifier – This identifies the particular country, geographical region, or language area of the publisher. 3.Publisher Prefix – This identifies the publisher of a given book. 4.Title Number – This is assigned by the publisher to a given title or an edition of a given title. 5.Check Digit – This validates the ISBN. These five sections are of varying lengths and separated by hyphens or spaces. Calculation of the Check Digit 1.Multiply each of the first 12 digits of the ISBN by alternate weights of 1 and 3; 2.Add all the weighted products together; 3.Divide the sum by 10 to determine the remainder; and 4.Finally subtract the remainder from 10 to derive the Check Digit.  If there is no remainder (i.e. the sum is divisible by 10), then the Check Digit is 0.