Australians preparing their own 2025–26 tax returns have until Monday, November 2, 2026, to lodge, with accountants warning that last-minute mistakes can leave taxpayers facing unexpected bills or questions from the Australian Taxation Office.
The usual October 31 deadline falls on a Saturday this year, moving the self-lodgement deadline to the following Monday. As of October 16, that leaves 17 days to get organised.
Missing the deadline can attract a failure-to-lodge penalty of up to $1,820 for an individual. But submitting an inaccurate return simply to beat the clock can create problems of its own.
Check Deductions
Work expenses are an obvious place to start, particularly for employees whose working arrangements changed during the year.
H&R Block tax communications director Mark Chapman told Yahoo Finance that taxpayers commonly overlook expenses such as professional subscriptions, union fees, work-related phone use and eligible travel.
Small payments deserve attention because their combined annual value can be easy to underestimate.
However, a payment appearing on a bank statement does not automatically make it deductible. Each claim needs to satisfy the relevant rules and relate to the financial year being reported.
Split Private Use
The opposite mistake is claiming more than the work-related share of an expense.
The ATO’s basic requirements are that you paid the expense yourself, were not reimbursed, and incurred it in earning your income. You also need supporting records. Where an expense serves both work and personal purposes, only the eligible work portion can be claimed.
For example, occasionally answering work calls on a personal mobile does not justify deducting the entire annual bill.
The calculation should reflect actual work use, supported by an appropriate method and evidence. Guessing a percentage because it looks reasonable can leave a claim difficult to explain later.
Home Office Costs
Working from home brings another opportunity for errors, especially when taxpayers copy figures from an earlier return.
Before claiming, check which calculation method applies and what evidence that method requires. Keep records of working hours and relevant expenses.
Under the ATO’s fixed-rate approach, a rough estimate of annual hours is not an acceptable substitute for the required record of actual hours worked from home.
A previous year’s deduction may also be a poor guide if office attendance, employment or household arrangements changed.
Review Pre-fill
Pre-filled information makes lodging easier, but it still needs checking.
Chapman warned that taxpayers should compare information already appearing in their return against their own records, rather than assuming everything has arrived correctly.
Review employment income, tax withheld, bank interest, dividends and health insurance details. Where something looks wrong, investigate the discrepancy before submitting.
Accountant Belinda Raso also told Yahoo Finance that incorrect information can appear across different categories.
A return containing pre-filled figures remains something the taxpayer needs to review carefully.
Find Missing Income
Side jobs and investments deserve a separate check because they may sit outside a person’s regular employment records.
Chapman identified freelance work, online platforms, investments and cryptocurrency transactions as areas taxpayers can overlook when relying heavily on pre-fill.
Check invoices, payment summaries, platform statements and investment reports against the return.
Someone who changed jobs or added a second source of income should also check that every relevant income source is included. An unfamiliar or missing entry is a reason to investigate, rather than submit and hope.
Remember Investments
Selling shares, cryptocurrency or an investment property can have capital gains tax consequences. The relevant calculation generally concerns the gain or loss on disposal, rather than treating all sale proceeds as profit.
Chapman also warned that reinvesting sale proceeds does not, by itself, remove the need to consider capital gains tax.
Crypto investors should pay particular attention to exchanges between assets. A crypto-to-crypto swap can be a disposal even when no Australian dollars reach a bank account.
Purchase records, transaction dates and disposal information therefore matter.
Know the Penalty
For individuals, the reported late-lodgement penalty starts at $364 for each 28-day period, or part thereof, overdue, reaching a maximum of $1,820.
That maximum is not an automatic charge immediately after the deadline. The ATO’s handling of a late return depends on the circumstances.
The Commonwealth penalty unit increased to $364 from July 1, 2026, making older penalty figures unsuitable for this deadline.
Seek Extra Time
Taxpayers considering professional help should engage a registered tax agent before October 31 and confirm their individual lodgement date. Eligible clients may receive a later deadline, but the same extension does not apply to everyone.
Before lodging, reconcile income, check deductions and save supporting documents. If something remains unclear, resolve it promptly so meeting the deadline does not depend on an unsupported guess.
