Question: My client was claiming part year threshold as he left Australian in January. He has a ton withholding from his interest income, but the system does deduct it from his tax payable. 

Answer: Make sure "Australian Resident" must be marked as "NO" since the taxpayer is not a resident for the whole financial year. Learn more here

Note, both ‘Gross interest’ and ‘TFN amounts withheld’ are not included in the amount payable when person was a foreign resident when received or was credited with the interest.

https://www.ato.gov.au/individuals-and-families/your-tax-return/instructions-to-complete-your-tax-return/paper-tax-return-instructions/2024/tax-return/income-questions-1-12/10-gross-interest-2024