Is H4 LEDr Legal? Why Dual-Beam Replacement Is More Difficult Than H11
Is H4 LEDr legal under UN R37 today? The short answer is no, not as a generally approved H4 LED replacement category. Our review of the official UNECE framework on 22 July 2026 found no in-force UN R37 H4 LEDr category sheet. A national approval tied to a vehicle positive list may cover a specific H4 product and specific vehicles, but that is a different approval route. Socket fit, an E-mark, or a supplier’s word “legal” does not close that gap.