The ERTMS Users Group is a European Economic Interest Group (EEIG) constituted by the Railway Administrations of France (RFF), Germany (DB), Italy (RFI), Spain (ADIF), The Netherlands (ProRail), United Kingdom (Network Rail) and Sweden (Banverket) plus SBB (Switzerland) as cooperating Partner.

Under the Aegis of the European Commission and of the European Railway Agency (ERA), the member railways are working in close co-operation with the European Infrastructure Managers (EIM), the Community of European Railway (CER) and the European Signalling Industries (UNISIG) for the harmonisation of the technical specifications and of the operational regulations of the European Rail Traffic Management System (ERTMS).