Core: Trailer coupling and licence plate

The coupling itself must always have an approval mark and be properly fastened, not seriously damaged, bent or rusted (book p.231) — this applies regardless of weight or which device you choose. After that it splits by weight: an UNBRAKED trailer up to 1,500 kg may run on an auxiliary coupling (a steel cable that activates the trailer's handbrake on breakaway) OR a breakaway braking device; above 1,500 kg the trailer must have a breakaway braking device. The two devices work in opposite ways and may therefore never appear together. For the licence plate, the trailer's own permitted maximum mass counts: up to 750 kg (also bike carriers that hide the car's plate from view) get a white plate with the same registration as the towing car; above 750 kg the trailer has its own registration certificate with a yellow plate and its own registration number. Before driving off you check one more thing: whether the lighting cable and the breakaway braking device or auxiliary coupling are fastened so the trailer can turn freely — up to an angle of 90 degrees — relative to the car (book p.232).