Australian National Towing Laws

In 1998, all Australian State Ministers of Transport formed an agreement which continues to form the basis of the country’s towing laws to this day. The agreement states very specific regulations pertaining to automobiles which have a gross vehicle mass not exceeding 4.5 tonnes. Unless the proper authority has granted approval, a trailer is not allowed to be towed if itsmass and/or load is over the recognisedcapacity and maximum mass set forth by the vehicle’s manufacturer.


According to the law, the maximum towing weight acceptable is the amount in which the vehicle’s manufacturer specifies or the capacity of the towbar. The one that is the least is the one you must obey. It shouldn’t be difficult to find out the towing capacity that is recommended by the manufacturer. Just look in the owner’s manual for the vehicle. It may even state this information in the vehicle’s sales brochure.

As for the towing capacity, it should at least be equal to the mass and load of the trailer together. However, it’s better if the towing capacity is higher just to be on the safe side. If you’re unsure about the towing capacity or how durable your towbar really is, then talk with the towing equipment expert who is selling or maintaining it.

You will come across some vehicle manufacturers which don’t mention the maximum towing capacity in terms of weight. In any event, you can just look at the regulations regarding it, such as:

  • If there are brakes installed on the trailer, it is legal to tow weight which is 1.5 times as much as the kerbweight or the trailer’s unladen mass.
  • If there are no brakes on the trailer, then the vehicle’s weight can be towed without any load on it.

The rules above rarely apply apart from using a truck to tow a trailer. But if you’re using a different type of vehicle to tow something like a boat trailer, caravan, or horse float, then you must adhere to the manufacturer’s recommendation about towing them.

If you own a 4-wheel drive vehicle or light commercial vehicle, you must ensure that they don’t go over its own Gross Combined Mass. The GCM is the most that a vehicle is legally allowed to weigh after you combine its own weight with the weight of its trailer (or load).

For instance, if you were to load a vehicle with camping supplies, suitcases, and 4 adults, this would likely cause the vehicle to go over the required GCM. You’d have to reduce the trailer mass in order to fix this. If you fail to lower the GCM, it could invalidate your warranty or any insurance policy that you have if an accident were to occur.

Speed Limits

In December 1998, legislation was passed which allows trailers to be towed on roads at the speed limits all over Australia, apart from Western Australia where the speed limit for towing trailers over 750kg is 100km per hour. But there are vehicle manufacturers who set their own speed limit recommendations and restrictions for a vehicle, depending on the amount of weight being towed.

For example, Ford says that if your load is under 1,200kg, then you should drive at about 100km/h. But if you’re hauling 1,600kg of weight, then you need to drive at around 90km/h. If you’re hauling 2,300kg of weight, you drive 80km/h. Notice a pattern here?

Another speed restriction relates to the type of towing equipment being hauled. To understand these restrictions and recommendations more thoroughly, you should take some time to read the owner’s manual and understand everything in the section pertaining to trailer towing.

State Agreements

Some states have different regulations about trailer towing, but there are some safety areas of it in which they agree upon, such as:

  • The weight of the trailer must be safe enough for the driver to control.
  • The trailer’s total mass or laden mass cannot exceed the recommended maximum mass set forth by its manufacturer. This can be found on the plate of the trailer.

The weight cannot go over the coupling’s specified load which is connected to the trailer using the fitted towbar. The tyres’permissible weight must also be considered too.

You must set up the trailer and towing vehicle appropriately so that you have the correct amount of combined weight. In other words, the towbar can only hold a load which is equal to about 10% of the trailer’s total weight.

Unbraked trailers must be under 750kg, if the trailer is above this weight it must be fitted with brakes.

Note: Because regulations and laws are constantly changing and or under review by federal and state authorities it is suggested that you check with your local state transport department before towing or operating your trailer, caravan or boat.

If you require your trailer, boat or caravan to be transported by a professional towing company in Perth contact Executive Towing Services on 0410 471 056.