The International Standard Book Number, ISBN, is a unique commercial book identifier barcode. The ISBN system was created in the United Kingdom, in 1966, by the booksellers and stationers W.H. Smith.

Originally, it was the 9-digit Standard Book Numbering (SBN) code and still was used in 1974; it was adopted as the international standard ISO 2108 in 1970. A similar, numeric identification, the International Standard Serial Number (ISSN), identifies periodical publications such as magazines. Since January 1, 2007, ISBNs are of 13 digits, like in Bookland EAN-13. The TC 46/SC 9 is responsible for the standard.

Overview 
An ISBN is given to each edition and variation (except reprintings) of a book. The ISBN is 13 digits long if assigned after January 1, 2007, and 10 digits long if assigned before 2007. An International Standard Book Number consists of 4 or 5 parts:

 for a 13 digit ISBN, a GS1 prefix: 978 or 979
 the group identifier code, (group of countries sharing a language) 
 the publisher code,
 the item number, and
 a checksum character or check digit.

The ISBN parts may be of different lengths, and usually are separated with hyphens or spaces.

The group identifier code (GIC) number is 0 or 1 for English-speaking countries; 2 for French-speaking countries; 3 for German-speaking countries; 4 for Japanese; 5 for Russian, et cetera. The original standard book number (SBN) had no group identifier, but affixing a zero (0) as prefix to a 9-digit SBN creates a valid 10-digit ISBN. The group identifier may be up to 5 digits long; e.g. 99936 is a group identifier for the country Bhutan.

The national ISBN agency assigns the publisher number (cf. the category: ISBN agencies); the publisher selects the item number. Generally, a book publisher is not required to assign an ISBN, nor for a book to display its number (except in China; see below), however, most book stores only handle ISBN bearing merchandise.

A listing of all the 628,000 assigned publisher codes is published, and can be ordered in book form, but, as of 2007, it costs US$300. The web site of the international ISBN agency does not offer any free method of looking up publisher codes.

Related pages

 Amazon Standard Identification Number (ASIN)
 CODEN (serial publication identifier currently used by libraries; replaced by the ISSN for new works)
 Digital Object Identifier (DOI)
 European Article Number (EAN)
 International Standard Audiovisual Number (ISAN)
 International Standard Music Number (ISMN)
 International Standard Recording Code (ISRC)
 International Standard Serial Number (ISSN)
 International Standard Musical Work Code (ISWC)
 Library of Congress Control Number
 PMID (PubMed ID)
 Serial Item and Contribution Identifier (SICI)

Footnotes

Other websites 

 ISO 2108:2005 at www.iso.org 
 Brief Summary of ISBN 
 How to find a book from Wikibooks
 ISBN to European Article Number EAS EBS CONELRAD transition at isbn.org
 Description of the ISBN to EAN upgrade process  at bookweb.org

National and international agencies
 International ISBN Agency—coordinates and supervises the worldwide use of the ISBN system. 
 ISBN Agency Australia —Thorpe-Bowker, a division of R R Bowker LLC
ISBN agency for UK and Republic of Ireland—Nielsen Book
 ISBN agency for US and Puerto Rico— R.R. Bowker LLC
 Numerical List of Group Identifiers  List of language/region prefixes

Online tools
 Special:Booksources, Wikipedia's ISBN search page.
 www.isbn.org/converterpub.asp Free 10-digit to 13-digit conversion tool from the ISBN agency. 
Can also use it to verify ISBNs to see if they are valid. Assures compliance with the full ISBN spec, not just the check digit.
 The ISBN tools website  has open-source Java classes to implement 10- and 13-digit ISBNs.
 Publisher access system for Books In Print and Global Books In Print database products
 ISBNdb.com—find books by ISBN, author, title, subject, et cetera; auto-corrects ISBN checksums if needed.
 ISBN.nu —offers free searching of a titles database.
 RFC 3187  Using International Standard Book Numbers as Uniform resource names (URN)
 ISBN-13 For Dummies 
 Implementation guidelines  (pdf document) for the 13 digit ISBN code.

Publishing
Book terminology
ISO standards