Deutsche Börse began the changeover to ISIN in November 2000 in a multiple-stage process. First, all relevant systems and applications were determined in the framework of a planning study, as well as the sequence of changeover activities that would be required. At the end of the fourth quarter of 2001 the exchange changed over the individual systems and applications to ISIN, step by step, starting with the central securities master data system. Comprehensive internal and external tests with customers of the Group ensured a smooth transition to the new identification number. The multiple stage process reduced potential risks, as compared with a "big-bang" approach. Since the end of November, ISIN is now the relevant identification number for the entire process chain from trading through clearing and settlement.
The exchange will continue to support the German securities identification number (WKN) on a parallel basis until the changeover has been made by the company Wertpapier-Mitteilungen as of April 22, 2003.
The ISIN is a 12-character code consisting of three components. A two-digit country code-such as DE for Germany-is followed by a national (local) code number with nine digits. The third component is a single numerical check digit. ISIN numbers are issued centrally in each country.