Australian Design Rules and state agencies decide whether a custom trailer can be plated and used. We translate ADR 38, ADR 13, ADR 62 and the registration counters without pretending this is legal advice.
Width and mass are different tickets. Most custom trailers in Australia fail on ATM, GTM or GCM long before they need an oversize permit — but 2.5 metres, 4.3 metres and a 19-metre combination are hard edges.
The ADRs are national. The queue is not. After a RAV entry and VIN, each Australian state and territory still wants its own inspection, weigh ticket and forms before a custom trailer gets plates.
ADR 13 is a lighting system, not a shopping list of LED lamps. Placement, approval marks, a working plate lamp and a plug that survives corrugations decide whether a custom trailer is visible — and registerable.
Unbraked light trailers in Australia usually stop at 750 kg GTM. Above that, ADR 38 decides between override, electric or air and hydraulic systems — and when breakaway becomes mandatory.
Australian Design Rules decide whether a custom trailer can be plated, entered on the RAV and registered. Here is how ADR 38, ADR 13 and ADR 62 actually show up in the workshop.