The prescribed rate of interest has been changed with effect from 1 May 2018 to 10% per annum. The previous rate was 10.25%.

According to the Prescribed Rate of Interest Act, interest on debts where no rate is prescribed is calculated at the repo rate plus 3.5%. The prescribed rate of interest applies to all debts unless a different rate is set by law, by trade custom or by agreement between the parties. The parties can therefore avoid the application of the prescribed rate by agreeing to a different interest rate, subject to other applicable laws such as the National Credit Act which may limit the amount of interest that can be charged.

When the Reserve Bank changes the repo rate a new prescribed rate of interest becomes effective from the first day of the second month following the month of the new repo rate announcement. The applicable rate of interest for any debt is the rate that is in effect on the due date for payment or the date of demand for payment where there is no fixed due date. That rate will continue to apply even if the prescribed rate of interest changes at a later date.

Here is a table for the changes in the prescribed rate since 1993.

Date range Rate of interest
1 October 1993 – 31 July 2014 15.5% pa
1 August 2014 – 28 February 2016 9% pa
1 March 2016 – 31 July 2016 10.25% pa
1 May 2016 – 31 August 2017 10.50% pa
1 September 2017 – 30 April 2018 10.25% pa
1 May 2018 – 10% pa