A tax deduction reduces your taxable income — and therefore the amount of income tax you pay. For every dollar you deduct, you save an amount equal to your marginal tax rate. At a 32.5% marginal rate, a $1,000 deduction saves $325 in tax. The key is understanding exactly which expenses qualify under ATO rules, and keeping the records to prove them.
Key Takeaways
- A deduction must be directly connected to earning your income — not private or personal use
- You must have spent the money yourself and not been reimbursed by your employer
- You must have a record: receipts, bank statements, or a diary for certain types of expenses
- The ATO data-matches and benchmarks deductions against occupation and income groups
The ATO’s Three Rules for Every Deduction
Before claiming anything, apply these three tests:
1. The expense must be incurred in earning your income. The expense must have a direct connection to your work activities. If you would not have incurred it but for your job, it passes this test.
2. It must not be private, domestic, or capital in nature. Clothing you could wear on a weekend (even if you wear it to work), meals during the day, and your gym membership are generally private. Buying an investment property is capital, not a deduction.
3. You must have records. Receipts for most expenses. A diary for home office hours, vehicle kilometres, phone usage, and overnight travel. Bank statements where receipts are unavailable. The ATO requires you to keep records for five years from the date you lodge the return they relate to.
How Deductions Reduce Tax
Your gross income minus allowable deductions = taxable income. Tax is calculated on taxable income, not gross income.
| Income | Deductions | Taxable income | Approx. tax (at 32.5% marginal) |
|---|---|---|---|
| $80,000 | $0 | $80,000 | ~$17,547 |
| $80,000 | $2,000 | $78,000 | ~$16,897 |
| $80,000 | $5,000 | $75,000 | ~$15,972 |
The saving is proportional to your marginal tax rate — higher earners save more per dollar of deduction.
Major Categories of Tax Deductions
Work-related expenses
The largest category for most employees:
- Working from home expenses — 67c/hour fixed rate or actual costs
- Car and vehicle expenses — logbook or cents-per-km (88c/km up to 5,000km)
- Clothing and uniform — occupation-specific, compulsory uniforms
- Tools and equipment — items under $300 claimed in full; over $300 depreciated
- Phone and internet — work proportion only
- Self-education — courses that maintain or improve skills in your current role
- Union and professional association fees — fully deductible
Investment-related expenses
- Interest on investment loans (rental property, margin loans)
- Account-keeping fees for investment accounts
- Rental property expenses — rates, insurance, management fees, repairs
- Depreciation on rental property assets
Other common deductions
- Income protection insurance — premiums on policies held outside super
- Charitable donations — to registered DGRs (Deductible Gift Recipients), $2 or more
- Prior year’s tax agent fee (deducted in the year paid, so last year’s fee is this year’s deduction)
What Cannot Be Claimed
| Expense | Why not deductible |
|---|---|
| Normal commute from home to work | Private travel — standard rule, regardless of how far |
| Everyday meals, coffee, groceries | Private expense |
| Gym membership (general fitness) | Not directly connected to earning income for most occupations |
| Child care | Private expense |
| Fines and penalties | Expressly prohibited |
| Ordinary clothing | Private — even if worn only to work |
| Capital expenditure (without depreciation) | Capital in nature — claimed over time as depreciation |
Record-Keeping Requirements
| Expense type | Record required |
|---|---|
| Most expenses | Receipt or invoice (paper or digital) |
| Small items < $10, total < $200 | Written note describing the purchase |
| Home office | Diary of hours worked at home (four-week representative or actual) |
| Vehicle (logbook) | Logbook for 12 consecutive weeks, plus odometer readings |
| Vehicle (cents/km) | No logbook needed, but written record of work trips is good practice |
| Overnight work travel | Travel diary if away more than 6 nights consecutive |
| Phone / internet | 4-week usage diary showing work vs personal proportion |
Records must be kept for five years from lodgement of the return they support.
The ATO’s Data Matching and Benchmarks
The ATO publishes occupation benchmarks and uses statistical profiling to identify returns where deductions are significantly higher than average for the income level and job type. This does not mean you should not claim what you are entitled to — it means you should ensure every claim is genuine and backed by records.
Commonly scrutinised areas: work-from-home claims, car expenses, tools and equipment for employees, and rental property costs.
Frequently Asked Questions
Can I claim deductions without receipts? For most expenses, yes — but you need some form of evidence. Bank statements, credit card records, or a written record (if you cannot get a receipt) are acceptable for the ATO. The default minimum is that you can prove you spent the money.
Do I need receipts for claims under $300? The $300 threshold in the ATO’s rules relates to tools and work-related equipment — items under $300 that are primarily for work use can be claimed in full without depreciation. It does not mean receipts are optional for any expense under $300; records are still required.
Is there a maximum I can claim for deductions? No fixed cap on total deductions — but all claims must be genuine and supportable. A large total deduction that generates a business or investment loss may be limited by specific loss rules.
What if I have both work and personal use for an item? You can only claim the work proportion. For example, if your phone is used 40% for work and 60% personal, you claim 40% of the cost.
This article provides general tax information. For advice tailored to your situation, speak with a registered tax agent. Find one through the Tax Practitioners Board register.