Before you hitch up a trailer, caravan, or boat, it's worth actually knowing what your vehicle and licence are legally allowed to tow — not just what the towbar itself is rated for. South African law looks at a few different numbers, and mixing them up is one of the more common mistakes.
GVM vs GCM — the two numbers that matter.
Your vehicle's GVM (Gross Vehicle Mass) is the maximum weight of the vehicle itself, fully loaded, on its own. Your GCM (Gross Combination Mass) is the maximum combined weight of the vehicle and whatever it's towing, together. Both are set by the vehicle manufacturer and are usually found on a compliance plate in the door jamb or engine bay, or in the owner's manual. A trailer that's within its own weight limit can still put you over your GCM if your vehicle is already loaded up — the two figures work together, not separately.
Your licence class matters too.
A standard Code B (light motor vehicle) licence covers towing a trailer with a GVM under 750kg — that covers most small utility and camping trailers. Once the trailer's GVM goes over 750kg (many caravans and loaded car trailers do), you legally need a Code EB licence to tow it, not just Code B. There are also weight-ratio rules between the vehicle and an unbraked trailer under 750kg — broadly, the tow vehicle's own tare weight needs to be at least double the trailer's weight for an unbraked trailer that size. If you're not sure which category your setup falls into, it's worth checking against the trailer's actual GVM rather than assuming your existing licence covers it.
The towbar's own rating is a separate limit again.
Even once GVM, GCM, and licence class are all fine, the towbar itself has its own maximum towing capacity and maximum vertical load (the downward weight on the tow ball itself, separate from the trailer's total weight) — both set by the towbar manufacturer for that specific vehicle. This is why a "universal" towbar rating doesn't really exist — it's rated per vehicle, because the vehicle's chassis and mounting points are what's actually taking the load.
A practical way to check before you tow anything unfamiliar:
- Find your vehicle's GVM and GCM (compliance plate or manual).
- Weigh (or find the rated weight of) whatever you're planning to tow, loaded.
- Check your towbar's specific rated towing capacity and tow-ball load for your vehicle.
- Confirm your licence code covers the combined weight.
If any one of those doesn't line up, it's not something to guess your way past — overloading a tow setup affects braking distance and vehicle stability, not just the paperwork.
Shopping for a tow bar rated for your specific vehicle? See our VW Polo, Toyota Corolla Cross, Toyota Fortuner or Toyota Hilux tow bar range. Want it professionally fitted? See our partner fitment areas.