The ATO doesn't audit everyone — but it does audit tradies more than most. The construction, plumbing, and electrical industries consistently feature in the ATO's compliance focus areas, partly because of high rates of cash income and partly because of the significant deduction claims associated with trade work.

Understanding what the ATO looks for — and what flags a return for closer review — lets you stay compliant, avoid scrutiny, and sleep a bit easier come June 30.

How the ATO Selects Audit Targets

The ATO uses data matching and risk profiling to identify returns that warrant closer examination. Their systems cross-reference:

  • Your income declarations against third-party data (bank statements, merchant payment data, property records, AUSTRAC reports)
  • Your deduction claims against industry benchmarks for your trade and income level
  • Your GST activity against what's expected for your revenue
  • Your single touch payroll (STP) reports against your tax return
  • Your lifestyle indicators (property purchases, vehicle registrations, travel) against declared income

The ATO also receives tip-offs from disgruntled clients, ex-employees, and competitors. And they conduct "random" audits that aren't actually random — they're disproportionately targeted at high-risk industries.

The bottom line: if your return looks unusual compared to similar tradies, it's more likely to be reviewed.

The Top ATO Audit Red Flags for Tradies

1. Lifestyle Inconsistent with Declared Income

If you declare $55,000 in taxable income but live in a $900,000 home, drive a new $80,000 ute, and just came back from a family Europe trip, the ATO's data matching will notice the discrepancy.

The ATO cross-references property purchases (from state revenue offices), vehicle registrations (from state transport departments), travel (from border control data), and social media. Yes, they look at Facebook and Instagram. A tradie declaring low income but posting photos of expensive holidays creates a digital red flag.

How to stay safe: Declare all income. If you have legitimate reasons for apparent lifestyle wealth — inheritance, partner's income, property equity — ensure your records support the explanation.

2. Cash Income Not Declared

The ATO knows which industries typically operate in cash. Construction, plumbing, electrical, and trade work are all on the list. The ATO conducts regular "cash economy" campaigns targeting tradies, and their data matching now includes information from major suppliers (Bunnings, Placemakers, wholesale suppliers) who report purchases.

If your supplier data shows you buying $80,000 in materials per year but your revenue shows only $100,000 in income — that's a margin that doesn't compute.

How to stay safe: Issue invoices for every job. Run all income through your business bank account. Even if a client offers cash, either bank it or deposit it immediately. "Cash in hand" jobs that don't appear in your records are a significant compliance risk.

3. Vehicle Claims That Don't Stack Up

Vehicle deductions are one of the highest-risk claims the ATO scrutinises. Common issues:

  • Claiming 100% business use on a vehicle that's clearly also used personally
  • Vehicle logbooks that appear to cover every single kilometre as business (implausibly high)
  • Claiming vehicle deductions without a logbook at all
  • Multiple vehicles claimed at 100% business use (how many vehicles is a sole trader plumber realistically operating for work?)

The ATO's benchmarks show what typical vehicle expense claims look like for your industry. Claims that significantly exceed these benchmarks attract attention.

How to stay safe: Maintain an accurate logbook for the required 12-week period. Be honest about personal use. If your ute does school runs or family trips, that's personal use and shouldn't be claimed.

4. Deductions Significantly Above Industry Benchmarks

The ATO publishes "small business benchmarks" for different industries and income levels. If your total deductions as a percentage of income are significantly higher than comparable businesses, it stands out.

For example, if electricians with $150,000 in revenue typically claim 35–40% in deductions but you're claiming 60%, expect closer scrutiny.

This doesn't mean you can't claim more than the average — if you have genuinely higher costs (more tools, more vehicle use, more training), you can claim them. But you need the records to support it.

How to stay safe: Know the benchmarks for your trade (available at ato.gov.au under "Small business benchmarks"). If your claims are significantly above average, ensure every dollar is documented with receipts.

5. Consistently Low Net Profit

If your trade business reports very low or zero profit year after year, the ATO wonders: how are you living? A business that consistently loses money or reports minimal profit isn't sustainable — which means either you have income not being declared, or you have personal expenses running through the business.

The ATO is particularly suspicious of:

  • Loss-making businesses that continue operating despite persistent losses
  • Net profit significantly below industry benchmarks for the revenue level
  • Businesses where the owner's declared income is lower than the cost of living

How to stay safe: Ensure personal expenses are not running through the business. Ensure you're pricing correctly. If your business genuinely makes low profit due to business conditions, have a clear explanation and documentation (loan statements, investor support, etc.).

6. Large or Unusual Deduction Claims Without Documentation

First-year businesses, businesses with sudden lifestyle changes, or businesses that suddenly claim dramatically different amounts from prior years can attract attention.

A sole trader electrician who has claimed $8,000 in tool deductions for three years suddenly claiming $45,000 in tool deductions will prompt questions.

How to stay safe: Keep receipts for everything. If you genuinely spent $45,000 on tools in one year, you have receipts and documentation. Don't be afraid of large legitimate claims — just ensure you can prove them.

7. GST Discrepancies

The ATO automatically cross-references your BAS income figures with your tax return income. If you've reported $400,000 in income on your BAS for GST purposes but $350,000 on your tax return, that's a discrepancy that demands explanation (and often there is a legitimate one — GST-exclusive vs GST-inclusive differences, etc.).

How to stay safe: Use accounting software that reconciles your BAS and tax return figures. Ensure your accountant reviews both before lodgement.

8. Inconsistent Super Contributions

The ATO matches super fund reporting with employer tax returns and STP data. If your STP shows you paid $200,000 in wages to employees but your super fund data shows $10,000 in contributions (which would be 5% — not the required 11.5%), that's a red flag.

How to stay safe: Pay super correctly and on time. 11.5% of ordinary time earnings for the 2025–26 year. Use payroll software that calculates this automatically.

9. Sharing Economy and Online Income Not Declared

Tradies who earn additional income through platforms — renting equipment on Hippo, selling tools or materials through Facebook Marketplace, teaching trade skills on YouTube — need to declare this income.

The ATO receives data from digital platforms and banks and can identify income streams not appearing in tax returns.

How to stay safe: Declare all income sources. If it's a business activity generating regular income, it's taxable.

10. Associates' Transactions That Look Like Profit Shifting

The ATO scrutinises transactions between related parties — paying your spouse a wage far above market rates, paying rent to a family trust at above-market amounts, or making loans to associates without proper documentation.

How to stay safe: All related-party transactions must be at arm's length — market rate wages, commercial rent, properly documented loans. Get your accountant to review any transactions with family members or related entities.

What Happens During an ATO Audit?

If selected for a review, the process typically escalates through stages:

1. Data-matching letter: "We've noticed a discrepancy in your return. Please explain..." This is the first level — often a written query requiring a response. Many queries are resolved here with documentation.

2. Desk audit: ATO staff review your documentation without visiting your premises. You submit records electronically. Most audits conclude at this stage.

3. Field audit: An ATO officer visits your business premises and reviews your records in person. Rare for small tradies, but possible for significant discrepancies.

4. Formal assessment: If the ATO determines you've understated income or overclaimed deductions, they issue an amended assessment with additional tax, plus interest and possibly penalties.

Penalties range from: 25% of the tax shortfall (for honest mistakes) to 75% or more for intentional evasion. Interest on unpaid amounts currently accrues at approximately 11% p.a.

How to Respond if You're Audited

  1. Don't panic. Many audits result in no adjustment — the ATO is checking, not necessarily assuming wrongdoing.

  2. Engage your accountant immediately. Don't communicate with the ATO directly about an audit without professional support.

  3. Gather documentation. Receipts, bank statements, logbooks, invoices — everything supporting your claims.

  4. Be cooperative. The ATO notes uncooperative responses and can escalate penalties accordingly.

  5. Seek voluntary disclosure. If you know you've made errors, a voluntary disclosure before the ATO identifies it themselves results in significantly reduced penalties.

Staying Audit-Safe: A Practical Checklist

  • ✅ Bank all cash income immediately — no "forgetting" to bank small amounts
  • ✅ Issue invoices for every job, no exceptions
  • ✅ Keep receipts for all deductions (digital copies are fine)
  • ✅ Maintain a 12-week vehicle logbook updated at the time of each trip
  • ✅ Separate personal and business expenses — no exceptions
  • ✅ Reconcile BAS and tax return income figures with your accountant
  • ✅ Pay super correctly and on time
  • ✅ Know your industry benchmarks and be prepared to explain any significant differences
  • ✅ Keep records for 5 years from tax lodgement date
  • ✅ Work with a qualified accountant — don't rely on DIY for complex claims

The ATO's Cash Economy Campaign — What Tradies Should Know

The ATO conducts ongoing targeted campaigns specifically aimed at the cash economy in construction and trade industries. These campaigns involve:

  • Visiting job sites to identify unregistered workers and contractors without ABNs
  • Requiring builders and subcontractors to report all payments to subbies (Taxable Payments Annual Report — TPAR)
  • Data-matching supplier records against declared income
  • Following up on tip-offs from the public

The Taxable Payments Annual Report (TPAR) requires builders, trade businesses, IT contractors, and several other industries to report all payments made to contractors annually. This data flows directly to the ATO and cross-references against contractor tax returns.

If you pay subbies and don't lodge TPAR — or lodge TPAR that doesn't match what subbies have declared — expect scrutiny.

Frequently Asked Questions

Q: Can I be audited even if I've done nothing wrong?
Yes. "Random" selection exists and is not truly random — it's risk-based. But some audits genuinely occur without specific red flags. The difference is that if you've done everything correctly, an audit is a minor inconvenience, not a financial disaster.

Q: How long does the ATO have to audit me?
Generally, the ATO can review a return for 2–4 years after lodgement (depending on your business type). For fraud or evasion, there's no time limit. This is why you keep records for 5 years.

Q: My accountant made an error — am I liable?
You, the taxpayer, are responsible for the accuracy of your tax return. Your accountant can be penalised for negligence, but you're liable for the tax debt. Choose a qualified accountant and review your return before signing.

Q: Can I reduce penalties by making a voluntary disclosure?
Yes. If you proactively come forward to correct an error before the ATO contacts you, penalties can be reduced by up to 80%. If you disclose after the ATO has made contact but before the audit concludes, penalties are still reduced but less dramatically.