The central feature of the ERM

The central feature of the ERM was the commitment by the participating countries to maintain their exchange rates in relation to one another and to the ECU within a margin of fluctuation of 2.25 percent. As an exception, Italy was given a margin of fluctuation of 6 percent, as were Spain and the United Kingdom when they joined. The ERM was not a fixed rate system: The central rates could be altered by negotiation among the participating governments.