Minutes of the twelfth meeting of the IWG on EV/HFCV Retrofit Systems held 28 September 2026. The group adopted the provisional agenda and reviewed the work program, aiming to provide GRPE with a first draft of a future UN Regulation by 14-16 October 2026. The group focused on revising definitions in the draft UN Regulation, particularly EPRS definition, EPRS type, vehicle family, and installer provisions. Key unresolved issues include which components must remain identical within an approved type, alternative ways of grouping vehicles within a family, whether installer requirements should be included in the UN Regulation, and the scope regarding vehicles subject to UN Regulations Nos. 155 and 156.