You MUST

	ensure all sidelights and rear registration plate lights are lit between sunset and sunrise
	use headlights at night, except on a road which has lit street lighting. These roads are generally restricted to a speed limit of 30 mph (48 km/h) unless otherwise specified
	use headlights when visibility is seriously reduced (see Rule 226).

Night (the hours of darkness) is defined as the period between half an hour after sunset and half an hour before sunrise. Laws RVLR regs 3, 24, & 25 (In Scotland – RTRA 1984 sect 82 (as amended by NRSWA, para 59 of sched 8))

You MUST NOT

	use any lights in a way which would dazzle or cause discomfort to other road users, including pedestrians, cyclists and horse riders
	use front or rear fog lights unless visibility is seriously reduced. You MUST switch them off when visibility improves to avoid dazzling other road users. (see Rule 226).

In stationary queues of traffic, drivers should apply the parking brake and, once the following traffic has stopped, take their foot off the footbrake to deactivate the vehicle brake lights. This will minimise glare to road users behind until the traffic moves again. Law RVLR reg 27

You should also

	use dipped headlights, or dim-dip if fitted, at night in built-up areas and in dull daytime weather, to ensure that you can be seen
	keep your headlights dipped when overtaking until you are level with the other vehicle and then change to main beam if necessary, unless this would dazzle oncoming road users
	slow down, and if necessary stop, if you are dazzled by oncoming headlights.