According to the Australian Design Rules, all trailers over 750kgs GTM (irrespective of the towing capacity or unladen mass of the tow vehicle) must have an effective brake system fitted. All brakes must be operable from the driver's seat of the tow vehicle except for over-ride brakes.

The minimum braking system required for a trailer or caravan depends on its type and weight, as well as the weight of the tow vehicle:

• Up to 750kgs GTM: No brakes are required.
• 751-2,000kgs GTM: There must be a braking system on the wheels of at least one axle and over-ride brakes are permitted. However, for caravans exceeding 1000kgs, independent brakes (electric brakes are the most common form) are strongly recommended.
• Over 2,000kgs GTM: A brake system operating on all wheels is required. The system must be capable of automatically activating should the trailer become detached from the tow vehicle. Under these circumstances the brakes must remain applied for at least 15 minutes. These 'break away' systems are compulsory on all trailers over 2,000kgs GTM.