You sure can! If you’re already a plate owner, simply visit your local Department of Transport and Main Roads Customer Service Centre to convert your plates for Large Trailer use. There’s no cost to do this, however, you will need to surrender one of your plates when converting.
Please note: there is a fee to convert plates from large trailer to motor vehicle class, which you will need to pay if you later decide to use your large trailer plates on your car. Fees also apply for conversions between Motor Cycles and Large Trailers and Motor Cycles and Motor Vehicles. For more information, visit your local Department of Transport and Main Roads Customer Service Centre.