The Informal Working Group on EV/HFCV Retrofit Systems held its eighth meeting on 21 April 2026. The group discussed cybersecurity principles, requiring retrofitted vehicles not to reduce safety or cybersecurity performance compared with UN R155 requirements, with differentiated approaches for base vehicles approved or not approved to UN R155. Braking compliance, EMC testing references, and UN draft regulation changes including renaming to “vehicles intended to be transformed into pure electric vehicles” and introducing Electric Powertrain Retrofit Systems definitions were addressed. PTI-related aspects and the need for written contributions were highlighted before providing the draft regulation to GRPE in October.