Within the EMS there is a European Currency Unit (ECU) which serves as a link and unit of account between member currencies. The ECU is not a currency in itself, however, but a “basket” of the currencies of 12 of the presently 15 EU states which contains, for instance, 62 German pfennigs, 1.33 French francs and 152 Italian lire. These amounts are no longer adjusted. Under the Treaty on European Union, the composition of the ECU basket was frozen.

In December 1991 a treaty was concluded in Maastricht by the then 12 EC states pursuant to which a European Economic and Monetary Union is to be completed by 1999 at the latest. Before they can participate in the final stage, states must fulfill strict criteria (stable prices and exchange rates, low interest rates, sound public finances). Participants in the Monetary Union have undertaken to transfer their monetary sovereignty to a politically independent European Central Bank, the foremost objective of which will be to maintain price stability. At the EU summit in Madrid in December 1995, it was resolved that the new European currency be called the “euro”. The new eurocash is to replace the national currencies in the year 2002.