For a single war widow/er receiving the ceiling rate of ISS, the deduction to be subtracted from his or her assessable income is given by the following equation:
Deduction = 2 × (assessed rate* of ISS - ceiling rate)
For a partnered war widow/er receiving the ceiling rate of ISS, the deduction to be applied to his or her assessable income is given by the following equation:
Deduction = (assessed rate of ISS - ceiling rate)
* assessed rate =rate payable if the ceiling rate did not apply.