The Australian Prudential Regulation Authority (APRA) has issued a discussion paper consulting on a formal three-tier approach to proportionality in its banking prudential framework, aimed at embedding additional differentiation by size and complexity. The proposals follow APRA’s commitment under the Council of Financial Regulators’ Review into Small and Medium-sized Banks. Under the proposal, a new tier of Most Significant Financial Institutions (MSFIs) would apply to banks with more than AUD 300 billion in assets, which would currently include the four major banks and Macquarie Bank. The second tier would cover all other significant financial institutions (SFIs), with the SFI threshold raised from AUD 20 billion to AUD 30 billion, and the third tier would comprise all remaining banks, including credit unions and building societies. Additional implementation time would be available for non-SFIs for new or revised requirements where appropriate, and APRA proposes a transition period of at least 12 months for any bank moving to a higher tier. Consultation runs for three months, and APRA expects to finalise the proposals in 2026.