The International Standard Book Number (ISBN) is an exclusive, numerical marketable book identifier. It normally based upon the 9-digit Standard Book Numbering (SBN) code, the ISBN was created in the United Kingdom by the booksellers and stationers W.H. Smith and others in 1966.

The 10-digit International Standard Book Number (ISBN) set-up was developed by the International Organization for Standardization and issued as an international standard, ISO 2108, in 1970; (conversely, the 9-digit SBN code was used in the UK until 1974). At present, the ISO TC 46/SC 9 is accountable for the standard.

Since 1 January 2007, International Standard Book Numbers are of 13 digits, well-matched with Bookland EAN-13s. The like numeric identifier, the International Standard Serial Number (ISSN), recognizes periodical publications like magazines.