can i build my own trailer in qld

Yes—you can build your own light trailer in Queensland, you just have to do it by the book rather than by the shed-rumour mill. It must comply with VSB1 (trailers up to 4.5 t ATM) and the relevant ADRs for lights, reflectors, tyres and couplings.

Get a VIN from TMR, stamp it, and fit a trailer plate with the VIN, ATM and build date; keep receipts for materials as proof you didn’t “find” it behind Bunnings. For brakes, under about 750 kg ATM no brakes are required, above that you’ll need service brakes, and at over 2,000 kg ATM you’ll need a breakaway system.

Make sure the lighting works (yes, including the number‑plate lamp), the safety chains and drawbar sizes suit the ATM, and the guards actually cover the tyres. Then book an inspection/registration with TMR, bring ID and a weighbridge ticket if asked, and walk out legal instead of lucky.