Do Australian banks withhold tax on interest?

 If your bank doesn't have your tax file number (TFN), it will withhold tax from your interest at the highest marginal tax rate. You can claim a credit for the amount of tax withheld when you lodge your tax return. You don't need to provide your TFN if: you're under 16 years of age.23 June 2025

https://www.ato.gov.au/individuals-and-families/investments-and-assets/investing-in-bank-accounts-and-income-bonds#:~:text=If%20your%20bank%20doesn't,under%2016%20years%20of%20age