How deductions really work
A deduction doesn't refund what you spent — it removes the amount from your taxable income, so the cash value is your marginal rate times the claim. For most full-time workers that's 30–37% plus the 2% Medicare levy, and with a HECS debt each deducted dollar also trims your repayment income. That's what the estimate above calculates properly: your salary, your bracket, your HECS — not a generic percentage.
The three golden rules decide everything. You paid for it yourself and weren't reimbursed; it directly relates to earning your income; you can prove it. The ATO's data-matching now compares claims against others in your occupation and income band — unusual claims without records are the audit trigger, not big claims with them.
Occupation matters because "work-related" looks different in different jobs: a tradie's sunscreen is deductible and an office worker's isn't; a nurse's registration is deductible while a first-time RSA certificate isn't. The checklist swaps in the items the ATO's occupation guides list for your line of work — use it before your tax-agent appointment so nothing gets forgotten.
The classic traps: normal commuting, ordinary work clothes, expenses your employer reimbursed, the private share of mixed costs, and study aimed at a career change rather than your current job. When a claim is partly private — phone, internet, car — only the work percentage counts, and you should be able to show how you worked it out.
This page is a general checklist, not personal advice. Whether an item is deductible for you depends on your facts and records — a registered tax agent can confirm, and their fee is itself deductible next year.