It is safest to assume that all the lights on your vehicle must be in working order – if they aren't you may commit an offence. However, there are exemptions in relation to a:
- rear fog lamp on a vehicle which is part of a combination of vehicles, any part of which is not required to be fitted with a rear fog lamp.
- rear fog lamp on a motor vehicle drawing a trailer.
- defective lamp, reflector, dim-dip device or headlamp levelling device on a vehicle in use on a road between sunrise and sunset, if any such lamp, reflector or device became defective during the journey which is in progress or if arrangements have been made to remedy the defect as soon as possible.
- lamp, reflector, dim-dip device, headlamp levelling device or rear marking on a combat vehicle in use on a road between sunrise and sunset.
- front fog lamp or a daytime running lamp on a vehicle which was first registered before 1st March 2018.