The first, and most annoying and unethical thing done by caravan and camper trailer manufacturers is giving false weight ratings. Every trailer you purchase in Australia should have a data nameplate on it, which specifies the empty weight of the trailer, its maximum weight, tyre sizes and axle ratings.
Time and time again this little nameplate is not true, mainly for the empty weight of the trailer (tare weight). Do not buy a trailer without first weighing it and seeing if the figure is correct. If its wrong, it eats into what you can carry on and in the trailer, and this is often already very low. On trailers where you might have 500kg of ‘payload’, sometimes they weigh 350kg over their empty weight, which gives you a measly 150kg to play with.
How is it possible for a trailer manufacturer to sell one trailer with a heap of additional accessories with an identical nameplate as another trailer with no accessories? They do this every day of the week! Nameplates are not individualised by most companies, and you are taking a shot in the dark by believing whats written on them.
Unfortunately this is not policed, and its causing people a lot of frustration, time and money. If you buy a trailer that weighs more than what it is supposed to, you lose some carrying capacity and the only way to get it back is to seek engineering or go back to the manufacturer. Either way, its not a path you want to have to take.