The Standard Book Numbering (SBN) code is a 9-digit commercial book identifier system created by Gordon Foster, Emeritus Professor of Statistics at Trinity College, Dublin, for the booksellers and stationers WHSmith and others in 1965. The ISBN configuration of recognition was generated in 1967 in the United Kingdom by David Whitaker (regarded as the "Father of the ISBN") and in 1968 in the United States by Emery Koltay (who later became director of the U.S. ISBN agency R.R. Bowker).
The 10-digit ISBN format was developed by the International Organization for Standardization (ISO) and was published in 1970 as international standard ISO 2108. The United Kingdom continued to use the 9-digit SBN code until 1974. ISO has appointed the International ISBN Agency as the registration authority for ISBN worldwide and the ISBN Standard is developed under the control of ISO Technical Committee 46/Subcommittee 9 TC 46/SC 9. The ISO on-line facility only refers back to 1978.
An SBN may be converted to an ISBN by prefixing the digit "0". For example, the second edition of ISBN 0-340-01381-8; the check digit does not need to be re-calculated.
Since 1 January 2007, ISBNs have contained 13 digits, a format that is compatible with "Bookland" European Article Number EAN-13s.