Highlights

  • About 142,000 people who lodged 2023–24 returns in early July later amended them, Services Australia says.
  • Self-preparers must lodge by 11:59pm on Monday 2 November, with payment generally due on 21 November regardless of lodgment timing.
  • For the first time, the ATO pre-fills about $21 billion in contractor payments for roughly 700,000 sole traders.
  • Leaving income out of a return does not hide it, the ATO warns, and unregistered preparers add further risk.

About 142,000 people lodged their 2023–24 tax return in the first two weeks of July, then had to go back and fix it, Services Australia says. Speed has a price. For self-preparers facing the 11:59pm deadline on Monday 2 November, a few minutes of checking could prevent a second round of paperwork, a smaller refund or an unexpected bill.

Why the deadline is Monday

The usual 31 October deadline falls on a Saturday this year, so people preparing their own return have until 11:59pm local time on Mon 2 November 2026. The ATO says delaying lodgment does not shift the 21 November payment date. As of 19 October, about 9 million returns had arrived, with about 2 million self-preparers still to lodge.

People who join a registered tax agent's client list by 31 October may be able to lodge later, until as late as May 2027 depending on eligibility. Late lodgment can attract failure-to-lodge penalties of up to $1,820.

The lesson from 142,000 amendments

The figure comes from a column by Services Australia's Hank Jongen, published in July. He wrote that the ATO passes income details to Services Australia a few weeks after lodgment, and that some taxable Centrelink payments do not pre-fill and must be added by hand.

Families feel it most. Family Tax Benefit and Child Care Subsidy are balanced against actual income, so an error can flow through to payments, and 5% of Child Care Subsidy is withheld each fortnight to limit overpayment.

Pre-fill and easily missed income

Pre-fill draws on more than 100 million pieces of data, yet tax communications director Mark Chapman cautions: "Pre-fill is useful, but people shouldn't treat it as a substitute for checking their own records." It can be incomplete early in the season, so bank interest, dividends, managed fund distributions and second-job income are worth checking against statements.

Omitted income is a Tax Time 2026 focus, including side hustles, cash jobs, interest and rent. The newly pre-filled contractor payments come through the Taxable Payments Annual Report and cover industries such as construction, couriers, cleaning, IT and security. The ATO estimates more than $1 billion of them could be omitted or under-reported.

Capital gains are another trap, since selling shares, cryptocurrency or an investment property can trigger one. Take a hypothetical employee on $80,000 who forgets $1,500 of bank interest. Taxed at 30% plus the 2% Medicare levy, the omission leaves $480 unpaid. If data matching spots the gap, the return would be amended and the $480 payable, possibly with interest and penalties on top.

Deductions, records and preparers

Work-related expenses are another ATO focus. Working-from-home claims under the fixed-rate method are 70 cents per hour, but records of the hours worked are needed.

Who prepares the return matters too. Returns held for suspected unregistered preparers claimed $170 million in deductions, and clients of those preparers lose safe harbour protection, which can shield taxpayers from some penalties when they rely on a registered agent.

Who still has to lodge

The ATO warns that retirees and lower-income earners may not realise they need to lodge. Selling an investment property, for example, creates an obligation. Tax withheld from wages can also produce a refund even when income is below the tax-free threshold.

Refunds drive the rush. In a July survey, 38% of Australians expected one, and 18% called a refund "critical" to their financial wellbeing. ATO Assistant Commissioner Anita Challen put the risk plainly: "When people rush to lodge, they're more likely to make mistakes or overlook important information."