5 ATO Tax Red Flags That Stop Your Refund in 2026
Is your tax return about to be flagged by an algorithm? Learn the 5 most common red flags the ATO uses to spot undisciplined taxpayers and how to protect your refund.
TL;DR — Quick Summary
- The Hook: The ATO uses AI and data-matching to flag "unusual" returns before you even get your refund.
- The Risks: Over-claiming laundry, generic "other" expenses, and mileage discrepancies are top triggers.
- The Cure: Keep itemized records and avoid "round number" guessing.
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Related: ATO Receipt Requirements Guide | Sole Trader Tax Deductions
The ATO is Not a Human—It’s an Algorithm
Many sole traders and contractors think they are "too small to be audited." In the past, that might have been true. But in 2026, the ATO doesn't need to send a person to check your books—they use sophisticated data-matching AI.
The algorithm compares your deductions against thousands of other taxpayers in your exact industry and location. If you’re an "outlier," your refund stops, and a letter arrives.
1. The Laundry Claim Trap
The ATO allows a $150 laundry claim without receipts. Every undisciplined taxpayer claims exactly $150.
The problem? You can only claim laundry if your clothing is "occupation-specific" or has a protective nature. If you work in an office and claim $150 for laundry, you’ve just raised a massive red flag.
2. Work-From-Home Overreach
Since the move to hybrid work, the ATO has cracked down on the "fixed rate" vs. "actual cost" methods. If you claim 100% of your internet and 100% of your phone bill as a business expense, you are asking for an audit.
3. The "Round Number" Red Flag
Beware of Zeroes
Real business life is messy. You spend $42.53 on fuel, not $50.00. You spend $118.90 on toner, not $120.00.
When a tax return is filled with $500 for travel, $200 for office supplies, and $300 for tools, it screams "I guessed." The ATO targets these returns first because they know you don't have the receipts to back them up.
4. Unexplained "Other" Expenses
The "Other" category is the favorite hiding place for undisciplined spenders. If this category exceeds 5% of your total claims without a clear description, the algorithm will flag it for manual review.
5. Inconsistent Income (TPRS)
If you’re a contractor in construction, cleaning, or IT, the ATO receives a Taxable Payments Annual Report (TPAR) from the person who paid you. If they report paying you $80k and you only report $70k, the system catches it instantly.
How to Audit-Proof Your Return
Don't Guess. Capture.
The easiest way to avoid red flags is to have a 1:1 match between your bank statement and a digital receipt. ReceiptClaimer does this automatically, so you never have to "round up" or "guess" again.