Look at the year across both employers

Each employer generally calculates withholding using the pay it gives you. It may not know what you earn elsewhere. With multiple sources of income, even if both payroll teams calculate their withholding correctly, the combined amounts can fall short of your annual liability.

For example, $75,000 from your main job plus $20,000 from weekend shifts gives $95,000 of employment income before deductions. Your return brings both jobs together. There is no separate annual income tax system just for the second job.

Check the declarations you gave payroll

For most Australian resident employees, claiming the threshold from both employers can mean too little tax is withheld. There is an exception where you are certain your total annual income from all sources will be $18,200 or less. Different rules can apply to foreign residents and part-year residents.

If your hours or income have changed, check your declarations rather than assuming last year’s settings still fit. You can ask an employer to withhold extra tax after reviewing your expected annual position.

Include your HELP debt in the review

If you have a HELP debt, tell each employer. Compulsory repayments use your annual repayment income, which can include more than salary. Amounts withheld by separate employers may not cover the repayment calculated across your total income.

Bring recent payslips from both jobs to a mid-year check. Include expected bonuses and other income so your estimate reflects the year you’re actually having.