Driven by the increasing demands on traceable measurement systems and calibration services, being able to fully cover the required needs, a large number of NMIs have put a great effort on the development of standardized wave shapes definitions, low voltage calibrators, measuring instruments and software for combined and composite high voltage tests. The European Metrology Programme for Innovation and Research (EMPIR) supports this work through the normative Joint Research Project 19NRM07 HV-com², which started in 2020 and has received funding from the EMPIR co-financed by the Participating States and from the European Union's Horizon 2020 research and innovation program.