Lodging an accurate tax return isn’t just about ticking boxes. The ATO’s data‑matching systems are more sophisticated than ever, and small mistakes can trigger big headaches.
Below is a clear breakdown of the most common pitfalls, why they matter, and how to stay safely off the ATO’s radar.
1. Incorrect Work‑Related Deductions
The ATO’s number‑one audit trigger is overclaimed or ineligible deductions. Their analytics compare your claims to others in similar occupations, industries, and income brackets.
Common traps
- Claiming standard amounts without evidence
- Deductions for items used partly for private purposes
- Claiming home‑office expenses without meeting the fixed‑rate method rules
- Incorrect motor‑vehicle logbooks or no logbook at all
ATO radar alert
If your deductions are significantly higher than the average for your occupation, the ATO’s systems flag it instantly.
2. Missing Income Streams
The ATO receives data directly from employers, banks, share registries, crypto exchanges, and government agencies. If you leave something out, they already know.
Commonly forgotten income
- Bank interest
- Dividends and franking credits
- Employee share schemes
- Side‑hustle or gig‑economy earnings
- Cryptocurrency disposals
- Foreign income
ATO radar alert
Unreported income is one of the fastest ways to trigger a review or audit.
3. Incorrect Rental Property Claims
Rental properties are a major focus area for the ATO, especially with the rise of short‑stay platforms.
Frequent errors
- Claiming interest on loans not fully used for the rental property
- Repairs vs. capital improvements
- Incorrect apportionment for holiday homes used privately
- Overstating depreciation
ATO radar alert
The ATO cross‑checks Airbnb and Stayz data, land titles, and bank loan information.
4. Not Keeping Adequate Records
The ATO requires records for five years, and they expect them to be complete, legible, and accessible.
Common issues
- No receipts for deductions
- Missing logbooks
- No evidence of working‑from‑home hours
- Lost or incomplete rental property records
ATO radar alert
If you can’t substantiate a claim, the ATO can disallow it — even if it was legitimate.
5. Mixing Personal and Business Expenses
For sole traders and small business clients, this is a classic problem.
Examples
- Personal meals claimed as travel
- Clothing that isn’t protective or occupation‑specific
- Home internet not apportioned correctly
- Vehicle expenses without business‑use evidence
ATO radar alert
The ATO uses industry benchmarks to detect unusual business expense patterns.
6. Incorrect GST Reporting
For clients registered for GST, errors in BAS reporting often flow into their tax return.
Common mistakes
- Claiming GST credits without valid tax invoices
- Not adjusting for private use
- Reporting cash vs. accrual incorrectly
- Forgetting to report GST on overseas digital services
ATO radar alert
ATO data-matching compares BAS, Single Touch Payroll (STP), and income tax returns for inconsistencies.
7. Capital Gains Tax Oversights
CGT is complex, and clients often underestimate what counts as a CGT event.
Common oversights
- Selling shares or crypto without reporting gains
- Incorrect cost‑base calculations
- Forgetting to apply (or incorrectly applying) the 50% discount
- Not reporting the sale of inherited property
ATO radar alert
Share registries, crypto exchanges, and property title offices all feed data directly to the ATO.
8. Relying on Pre‑Fill Too Early
Pre‑fill is helpful, but it’s not complete until late July or even August.
Risks
- Missing bank interest
- Missing private health insurance statements
- Incomplete employer Single Touch Payroll (STP) data
- Missing dividends
ATO radar alert
If your return doesn’t match the data the ATO receives later, they will amend it — and may apply penalties.
9. Not Seeking Professional Advice
Many mistakes happen simply because clients try to do it themselves or rely on outdated information.
Benefits of professional guidance
- Correct deductions
- Accurate income reporting
- Strategic tax planning
- Reduced audit risk
Should you require further information on avoiding mistakes when lodging your tax return, please feel free to contact Sarthak Sobti by submitting an enquiry or by calling us on +61 2 9580 9166.
The information in this document does not take into account your personal objectives, financial situation, or needs, so you should consider its appropriateness having regard to these factors before acting on it. It is important that your personal circumstances are taken into account before making any financial decision and it is recommended that you seek assistance from your financial adviser