Stamp Duties Consolidation Act 1999 section 159D

Calculation of interest on unpaid duty and other amounts

Section 159D sets out a standard formula for calculating interest on unpaid stamp duty and other amounts due under the Act, applying daily interest rates that depend on when the period of delay occurred.

• Interest on unpaid duty is calculated using the formula A x D x P.
• A is the unpaid amount, D is the number of days of delay (including part of a day), and P is the daily percentage rate.
• The daily rate is 0.0273% for the period 1 April 2005 to 30 June 2009, and 0.0219% from 1 July 2009 onwards.
• Where a period of delay spans both rates, interest is calculated separately for each part and the amounts are aggregated.