In the US you trade the tank in for a freshly inspected and filled tank. You don’t pay for the inspection separately.
And you don’t need any kind of moisture trap. There’s zero moisture to trap, period.
That makes sense. I would hate to get a tank and have to have a required extra $40 or so every year. Thought it would be similar to how I normally work my propane tank for grilling..........just trade in the tank for a full/inspected tank VS filling the tank I turned in.