A Bill which appropriates revenue or moneys or imposes any form of taxation.

Under the Constitution, the government can only impose taxes, raise or 'appropriate' revenue, or spend Commonwealth money where that has been authorised by the Parliament through legislation. The term 'money bill' refers to a bill that: imposes taxes; raises or appropriates revenue; or appropriates or authorises the spending of money. The Constitution does not allow the Senate to initiate or amend some types of money bills.

Bills relating to financial matters are sent to the Ways and Means or Counties Commission of the respective.

In the Westminster system, a money bill or supply bill is a bill that solely concerns taxation or government spending (also known as appropriation of money), as opposed to changes in public law.