In both houses of the Australian Parliament, a tied vote is a ‘no’ vote. The Australian Constitution requires that questions ‘shall be determined by a majority of votes’. Without a majority voting ‘yes’, the question (e.g. ‘should the bill be read a second time?’) is defeated and the house does not continue with that action.
In practice, the majority vote works a little differently in each house.
Section 40 of the Australian Constitution explains that the Speaker of the House of Representatives will only vote if there is a tie. This is called a ‘casting’ vote. Traditionally, the Speaker votes ‘yes’ if the question will allow the House to continue debate, but abstain—not vote—if the question is to make a final decision on a bill.
Section 23 of the Australian Constitution requires that in the Senate all senators—including the President—vote. This ensures that each state is equally represented. It also means that a tied vote immediately fails, as the President has already voted and cannot resolve a tie.