In Australian law, a penalty unit (abbreviated as PU) is an amount of money used to compute pecuniary penalties for many breaches of statute law. Fines are calculated by multiplying the value of one penalty unit by the number of penalty units prescribed for the offence.
The different jurisdictions that make up Australia (the Commonwealth and the states and territories) each have their own penalty units. The value of a penalty unit, and the manner and frequency of varying that value, differ from state to state, and there are also federal penalty units that apply only to federal offences.
In the state of Victoria, the value of a penalty unit is the amount fixed with respect to a financial year by the Treasurer by notice published in the Government Gazette under the Monetary Units Act 2004. The penalty unit rate is fixed at A$155.46 as of 1 July 2016. Therefore, a fine defined as 100 penalty units would incur a penalty of $15,546 (rounded to the nearest 10 cents). One penalty unit in New South Wales is $110. One penalty unit in Queensland is $121.90
In the state of Tasmania the value of a penalty unit is adjusted for each financial year based on consumer price index (CPI) movements in the previous year, and published in the Tasmanian Government Gazette before 1 June for the next financial year. In the 2017 financial year it is $157.
Under Australian federal law a penalty unit for an individual is $180 as of 31 July 2015.
Western Australian penalty units vary across the legislation, most are listed as a dollar figure in the legislation, but road offences incur a penalty unit of $50.
South Australia does not have penalty units. Instead, fine amounts are listed in the legislation.
Rationale
In earlier times, fines and other charges were usually prescribed in terms of ordinary money (pounds or, later, dollars). However, the effects of inflation meant that originally substantial penalties were eventually reduced to trifling sums. Frequent amendment of the many laws and regulations dealing with pecuniary penalties would be a very time-consuming process. Penalty units provide a quick and simple way to adjust many different fees and charges.