Given that Australia does not require proof of Intent-To-Use prior to accepting trademark applications, the filing of multi-class trademarks is a much simpler and less risky proposition than in other countries.

The only major pit-fall of multi-class trademark applications in Australia is that you only have three years after the filing of the trademark to begin using it. If you make a multi-class application in classes which you have no intent to use, you may eventually face challenges to your trademark in those classes.