Additional tax on superannuation contributions at the rate of 15% is imposed on individuals whose combined income and contributions are greater than a certain threshold. From 1 July 2017 this threshold is $250,000. Prior to this it was $300,000. For affected individuals, this effectively increases the rate of tax on their superannuation contributions from 15% to 30%.
The additional tax can be paid personally by the taxpayer or the taxpayer can apply to his/her superannuation fund to have the necessary amount released and paid to the ATO.