Glad you have it simple down there. Up here we have a "Yellow Sticker" which is required on any trailer/truck combination above a certain amount. Sticker on the truck and one on the trailer. Each one requires a safety and renewal every year. Fine, but we are also told that trailer wearing a yellow sticker can only be towed by a stickered truck...even if the trailer is empty. And every trailer that the truck tows must also have a sticker no matter what the total weight will be.....
When you ask in person you get the book quoted but not explained...oh, and a 3/4ton Ford with four passengers and four ATVs on a trailer is enough weight to require a sticker..