International Standard Book Number

The International Standard Book Number (ISBN) is a unique numeric commercial book identifier based upon the 9-digit Standard Book Numbering (SBN) code created by Gordon Foster, Emeritus Professor of Statistics at Trinity College, Dublin, for the booksellers and stationers W.H. Smith and others in 1966.

The 10-digit ISBN format was developed by the International Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108. (However, the 9-digit SBN code was used in the United Kingdom until 1974.) Currently, the ISO’s TC 46/SC 9 is responsible for the ISBN. The ISO on-line facility only refers back to 1978.

Since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with Bookland EAN-13s.

Occasionally, a book may appear without a printed ISBN if it is printed privately or the author does not follow the usual ISBN procedure; however, this is usually later rectified.

A similar numeric identifier, the International Standard Serial Number (ISSN), identifies periodical publications such as magazines.

R.R. Bowker is the U.S. Agency of the International Standard Book Numbering Convention, as approved by the International Organization for Standardization. As such, it is the originator of ISBNs for U.S.-based publishers. Authors of self-published books can purchase an ISBN for $125.00. Publishers in other countries can only obtain ISBNs from their local ISBN Agency, a directory of which can be found on the International ISBN Agency website.