The deadlines for your 2025–26 tax return, when any tax owing is due, and the penalty for lodging late.
Key facts
- If you lodge your own 2025–26 tax return, it's due by 31 October 2026, and any tax owing must be paid by 21 November 2026.
- If you use a registered tax agent, you must engage them before 31 October 2026; most of their clients then have until 15 May 2027.
- Agent clients with outstanding returns from earlier years are due 31 October 2026, and those whose last return had a tax bill of $20,000 or more 31 March 2027.
- The failure to lodge penalty is 1 penalty unit ($364 from 1 July 2026) for each 28 days or part of 28 days late, up to 5 units ($1,820) for an individual.
- The ATO can also charge the general interest charge on tax paid late.
Lodging it yourself
| What | Due |
|---|---|
| Lodge your 2025–26 tax return | 31 October 2026 |
| Pay any tax owing | 21 November 2026 |
Through a registered tax agent
| Due | Who |
|---|---|
| 31 October 2026 | Prior-year tax returns were still outstanding at 30 June 2026 |
| 31 March 2027 | Your latest return had a tax liability of $20,000 or more |
| 15 May 2027 | Everyone else on a registered tax agent's list (5 June if any tax owing is also paid by then) |
Paying tax for returns due 15 May 2027
| When the return is lodged | Payment due |
|---|---|
| Lodged by 12 February 2027 | 21 March 2027 |
| Lodged 13 February to 12 March 2027 | 21 April 2027 |
| Lodged from 13 March 2027 | 5 June 2027 |
Late lodgment penalty calculator
| Days late | Penalty units | Penalty (individual) |
|---|---|---|
| 1 days | 1 | $364 |
| 28 days | 1 | $364 |
| 29 days | 2 | $728 |
| 60 days | 3 | $1,092 |
| 100 days | 4 | $1,456 |
| 140 days | 5 | $1,820 |
| 365 days | 5 | $1,820 |
Penalty unit $364 for documents overdue on or after 1 July 2026. Medium withholders pay 2 times and large withholders 5 times the base penalty.
Common questions
When is the tax return deadline in Australia?
31 October 2026 for the 2025–26 income year if you lodge it yourself. Through a registered tax agent it's later, usually 15 May 2027, if you're on their list by 31 October 2026.
What happens if I lodge my tax return late?
The ATO can charge a failure to lodge penalty of $364 for each 28 days late, up to $1,820, plus interest on any tax paid late.
When do I have to pay my tax bill?
If you lodge yourself, by 21 November 2026. For tax agent clients due 15 May 2027, the payment date depends on when the return is lodged: lodged by 12 february 2027: 21 March 2027; lodged 13 february to 12 march 2027: 21 April 2027; lodged from 13 march 2027: 5 June 2027.
Can I still use a tax agent after 31 October?
Only if you were on the agent's list (engaged them) before 31 October 2026. Otherwise your return is due 31 October 2026 like a self-lodger's.
See also the tax refund calculator, ATO interest rates and the tax-free threshold.
Sources: ATO preparing your tax return, registered agent lodgment program, failure to lodge on time penalty and penalty units. Checked 22 October 2026.