Note: this article describes the regulations in force in Poland. Requirements in other countries may differ – check your local rules.
Mandatory trailer lighting – what the regulations say
The basis is the Regulation of the Minister of Infrastructure of 31 December 2002 on the technical conditions of vehicles and the scope of their necessary equipment (Journal of Laws (Dz.U.) 2024, item 502, as amended). Below I have collected the requirements for car trailers, agricultural trailers and other towed vehicles.
Text updated 29.10.2026 – consistent with the regulation as worded in Dz.U. 2024, item 502, as amended.
Mandatory lighting on every trailer
- Direction indicators
- Stop (brake) lamps
- Rear registration plate lamp
- Rear position lamps
- Rear triangular reflectors
- Front reflectors
- Side reflectors
- Hazard warning lights
- Rear fog lamps ¹
¹ A trailer towed by an agricultural tractor, a forestry tractor or a slow-moving vehicle does not have to be fitted with a rear fog lamp.
Several of these functions can be combined in a single combination lamp – you will find rear combination lamps for trailers at zemot.com.pl.
Mandatory lighting depending on dimensions and mass
- Width ≥ 1.6 m: front position lamps
- Width > 2.1 m:front and rear end-outline marker lamps
- Length including drawbar > 6 m:side marker lamps
- GVW > 750 kg (trailers registered after 01.08.2009): reversing lamp
- GVW > 3.5 t and width > 2.1 m: rear retro-reflective contour marking
- GVW > 3.5 t and length > 6 m (trailers registered after 10.10.2009): side retro-reflective contour marking
- Length including drawbar > 10 m or GVW > 10 t: rear marking plates – yellow retro-reflective with a red fluorescent border
Exactly where to mount these lamps – distances from the edges, spacing and heights – is described in the article How to position the lights on a trailer. The colours that end-outline marker lamps must have are explained in LED marker lamps – colours and regulations.
These are the rear marking plates for long and heavy vehicles (rectangular, retro-reflective and fluorescent), mandatory in road haulage. They do not apply to trailers towed by agricultural tractors, forestry tractors or slow-moving vehicles – these have their own marking, described below.
Additional requirement for agricultural and slow-moving trailers
A different plate is the triangular slow-moving vehicle plate. Every slow-moving vehicle must carry one, as must any trailer towed by an agricultural tractor, a forestry tractor or a slow-moving vehicle. The plate is not required on a trailer that is not the last vehicle in the combination.
The full requirements for tractors, machines and agricultural trailers are collected in the article Lighting and marking of agricultural vehicles, machines and trailers.
What can be fitted in addition?
As a rule, fitting lighting other than the mandatory lighting on trailers is prohibited. The regulations do, however, allow a number of exceptions:
- Front position lamps – permitted on every trailer
- Side marker lamps – permitted on every trailer
- Front and rear end-outline marker lamps – permitted on trailers from 1.8 m to 2.1 m wide (wider ones must have them)
- Reversing lamp – permitted on every trailer (including those with a GVW up to 750 kg and those registered before 01.08.2009)
- Rear reflectors other than triangular – permitted on every trailer
- Retro-reflective contour marking – permitted on trailers with a GVW > 750 kg
- Work lighting – permitted
Older trailers
For trailers registered before 1990, the regulation provides a number of exemptions from the mandatory equipment. If you have doubts about a specific trailer, write to zemot@zemot.pl – we will give you a specific answer.