The Tasmanian Security of Payment Act provides for interest at s15(3) of the Act as follows:

(3) Interest is payable, on the unpaid amount of a progress payment that has become due and payable, at the rate –

(a) prescribed under the Supreme Court Civil Procedure Act 1932 in respect of a judgment for money payable to a person; or

(b) specified in the building or construction contract –

whichever is greater.

Tasmanian practitioners should note that the Supreme Court Civil Procedure Act 1932 can be found here at this link and the prescribed rate of interest can be found here.