Key Dates for 2025–26 Returns
| Action | Date |
|---|---|
| Financial year ends | 30 June 2026 |
| MyGov pre-fill data available | ~Late July 2026 |
| Self-lodgement deadline | 31 October 2026 |
| Tax agent deadline (most clients) | 15 May 2027 |
| Payment due (if you owe) | 21 November 2026 (self) or as assessed |
What Happens If You Lodge Late
The ATO can charge a Failure to Lodge (FTL) penalty of $330 for every 28-day period your return is late, up to a maximum of $1,650 (5 × $330 — the Commonwealth penalty unit rose to $330 on 7 November 2024). If you owe tax, you'll also be charged interest on the outstanding amount (the general interest charge, updated quarterly) — and from 1 July 2026 that interest is no longer tax-deductible, so a tax debt costs more than it used to.
Using a Tax Agent
If you register with a tax agent before 31 October, you generally get an extended deadline — usually 15 May of the following year. But you must be registered with the agent before the original deadline, not after.
Tip: Wait Until Late July
If you lodge too early in July, your MyGov pre-fill data might be incomplete — your employer, bank, and health fund may not have submitted everything to the ATO yet. Waiting until late July or August means most data is pre-filled, reducing errors and maximising your refund.
Frequently Asked Questions
What if I've missed previous years?
Lodge them as soon as possible. The ATO is more lenient with voluntary lodgements than with people they have to chase. You may still face penalties but they're often reduced.
Do I need to lodge if I earned under $18,200?
Not always, but it's usually worth it. If tax was withheld from your pay, lodging gets you a refund. If you have a HELP debt, you still need to lodge.
Can I get an extension?
Contact the ATO before the deadline if you have a genuine reason (illness, natural disaster, etc.). They can grant extensions on a case-by-case basis.