This may come as a surprise to some, but trailer lighting rules vary depending on a number of factors. To help keep you safe and legal (especially during the darker times of the year), we have prepared an easy-to-follow guide on the trailer lighting rules.

The different types / classes of trailer are as follows:-

• O1 Trailers – Very lightweight trailer with a GVW of 750kg or under.
• O2 Trailers – Lightweight trailer with a GVW from 750kg to 3500kg.
• O3 Trailers – Heavy duty trailer with a GVW between 3.5T to 10T.
• O4 Trailers – Heavy duty trailer with a GVW over 10T.

This guide is aimed at Class O1 and O2 trailers as these are able to be towed by a car, van or pickup. They will be unbraked (O1) or fitted with an overrun braking system (O2) and have a gross vehicle weight (GVW) of 3500kg or below.

Standard Lights Required on all trailers

Listed below are the basic lighting rules that cover all trailers until they reach 1.3m wide.

• 2 Side/tail lights with red lens
• 2 Direction indicators with amber lens (designed to flash between 60 and 120 times per minute)
• 2 Brake lights with red lens
• Illumination for number plate

All must also have the following reflectors.

• 2 White/clear front reflectors
• 2 Red rear triangular reflectors
• 2 Amber side reflectors (minimum) dependant on length

The above rules apply to lightweight trailers up to 1300mm wide (overall). More than 2 side reflectors are required if the trailer is over 2900mm long (including the drawbar).

The requirements for trailers over 1300mm wide

At an overall width of 1300mm additional to the standard lights the trailer will also need the following:-

• 1 Fog light (minimum) with red lens (if only one light fitted, it must be positioned to the offside of the centre line of the trailer)

NB. Overall width is at the trailer’s extreme width, including mudguards if fitted outboard.

The requirements for trailers over 1600mm wide

At an overall width of 1600mm, in addition to the standard lights and a fog light, the trailer will also need the following:-

• 2 White/clear front position lamps (in addition to reflectors – these can be a one-piece unit)
• 1 Reverse light (minimum) with clear lens (if only one light fitted, it must be positioned to the nearside of the centre line of the trailer)

NB. The fitting of a reverse light will also necessitate the use of a 13pin Euro plug.

The use of this guide will help you stay on the right side of the law whan it comes to trailer lighting rules!