For the 2025-26 financial year, the top marginal income tax rate of 45 per cent applies to taxable income above $180,000.

The threshold at which the top bracket starts: $180,000

The controlling authority that sets resident individual income tax rates is the Australian Parliament (specifically, the legislature that enacts the Income Tax Assessment Act 1936 and related taxation legislation). The Australian Taxation Office (ATO) administers and enforces these rates, but Parliament is the authority that sets them through legislation.