You don't pay tax on your whole salary — you pay tax on what's left after legitimate work expenses come off the top. That's what "claiming a deduction" means: you lower the income the ATO taxes.

So a work expense isn't fully out of your pocket. The ATO effectively chips in your marginal tax rate of every dollar you claim — because that's the tax you no longer pay on it. The higher your rate, the more the system shares the cost.

This exact lever, scaled up, becomes salary-sacrificing into super, and negatively gearing a property. Same idea, bigger numbers.

Every employee with work-related costs — and even more so if you're a sole trader or run a side business. Three rules decide if something counts:

Common ones: working-from-home running costs, a car used for work (not the commute), tools and equipment, self-education tied to your current job, union or professional fees, and income-protection insurance held outside super.

Say you earn $90,000 and spend $2,000 on genuine work expenses across the year. At $90k, your marginal rate is 32% (30% tax + 2% Medicare).

$640 back, not $2,000. The deduction shares the cost with the ATO at your rate — it doesn't refund the whole thing. That's the honest truth most "tax hacks" skip.

At your rate, the ATO effectively pays 32¢ of every $1 you claim. Slide the amount to see it move.