The request sought the estimated cost to the budget, from 2017-18 to 2030-31, of the Government’s Personal income tax plan. The baseline for this analysis is keeping the personal income tax rates, thresholds and offsets the same as they were in 2017-18 over the period to 2030-31.

The tax plan was announced in the 2018-19 Budget measure Personal Income Tax Plan, the 2019-20 Budget measure Lower taxes for hard-working Australians: Building on the Personal Income Tax Plan and the 2020-21 Budget measure JobMaker Plan – bringing forward the Personal Income Tax Plan and retaining the low and middle income tax offset.

The request also sought the estimated total cost and percentage of total cost attributed to each quintile by taxable income for individuals lodging a tax return.