In March 2021, the DVSA issued a special notice: MOT special notice 01-21: headlamp conversions. This detailed changes to MOT testing rules for headlight conversions using high-intensity discharge (HID) or light-emitting diode (LED) bulbs.
This notice states that Class 1 and 2 motorcycles must not be failed for the defect ‘Light source and lamp not compatible’. Headlamps must comply with all other requirements of the test and headlamp aim. For class 3,4,5 and 7 vehicles, the defect ‘Light source and lamp not compatible’ only applies to vehicles first used on or after 1 April 1986. Should a vehicle be presented for an MOT test with conversions before 1 April 1986 they must not be failed with immediate effect. Vehicles presented with converted halogen headlamp units first used on or after 1 April 1986 will continue to be failed. Headlamps must comply with all other requirements of the test and headlamp aim.