From www.smartcompany.com.au: Starting July 1, 2025, interest on overdue ATO debts, specifically the General Interest Charge (GIC) and Shortfall Interest Charge (SIC), will lose their tax deductibility following the passage of new legislation aimed at increasing tax revenues by $500 million annually.

This reform, announced by the Albanese government in December 2023, seeks to enhance tax compliance by encouraging timely self-assessment of tax liabilities.