The tax return deadline for people who lodge their own 2025-26 return is 31 October 2026. Clients of a registered tax agent can usually lodge later, often well into 2027, but only if they are on the agent’s client list by 31 October and their tax history does not trigger an earlier date. A self-lodger, a first-time agent client, someone two years behind and someone who owed a large amount last year can all have different due dates for the same return.
This guide sorts you into the right row using the Australian Taxation Office (ATO)’s own published dates, then explains the one step that has to happen before 31 October.
Your tax return deadline at a glance
Source: ATO, Individuals and trusts due dates, last updated 1 July 2026.
If you lodge your own return through myTax or on paper
Your 2025-26 tax return is due by 31 October 2026.
When is a tax return due if you miss that date? It is still due straight away, and a late lodgement can attract a penalty. Here is how the ATO’s failure to lodge on time penalty works for individuals:
- The rate: one penalty unit for every 28 days (or part of 28 days) the return is overdue
- The cap: a maximum of five penalty units
- The value: one penalty unit is $364 for infringements on or after 1 July 2026 (ATO, Penalty units, last updated 26 June 2026). Five units comes to $1,820.
The ATO also says it generally does not apply penalties in isolated cases of late lodgement, and it will warn you before applying one. It generally will not issue a penalty for a late return that results in a refund or a nil result.
If you use a registered tax agent
Most registered tax agents run a lodgement program that lets them lodge for clients after 31 October. The catch is timing. The ATO says that if you are using a tax agent for the first time, or switching agents, you should contact them before 31 October to be part of their program (ATO, Lodge with a registered tax agent, last updated 24 April 2026).
For most people on an agent’s list, the tax return due date is:
- 15 May 2027, or
- 5 June 2027 under a concession, provided any payment owing is also made by that date
That extra time is the main reason people use a tax agent lodgement program, but it only works if you are on the list in time.
The two exceptions that bring your date forward
Even with an agent, two situations move your deadline earlier:
- You had overdue tax returns. If one or more prior-year returns were still outstanding at 30 June 2026, your 2025-26 return is due 31 October 2026. That means all prior years, not just last year. The ATO says that if every outstanding return is lodged by 31 October 2026, the normal program dates apply again.
- You had a big tax bill last year. If your latest return showed a tax liability of $20,000 or more, your return is due 31 March 2027.
These are the two rows people most often miss, and they are why “I use an accountant, so I have until May” is not always true.
What “on the client list” actually means
Being on an agent’s client list means you have engaged that agent and they have added you to their list with the ATO before 31 October. It does not mean your return has to be lodged by then.
A few points worth knowing:
- A phone call is not always enough. Confirm with the agent that you have actually been added, not just that they will “get to it”.
- Changing agents counts as starting again. Tell your new agent before 31 October.
- The program is a concession. The ATO says it can ask for documents to be lodged earlier than the program dates.
It is also worth checking that your agent is registered on the Tax Practitioners Board public register. Only registered tax agents can charge a fee to prepare your return.
Do you need an agent at all? An honest answer
Not everyone does. A simple return with wages, bank interest and a few standard deductions is very manageable in myTax, especially once your income statement is marked “tax ready”.
A registered tax agent usually earns their fee when your return includes:
- a rental property
- sole trader or business income
- capital gains, such as shares or crypto
- one or more late tax returns from earlier years that need catching up
For sole traders, our sole trader tax time checklist covers what to gather first. And if your return is already lodged but the refund is slow, here are seven reasons a refund can stall.
Getting on a list in Williams Landing or Melbourne’s west before 31 October
We are a registered tax agent in Williams Landing, working with individuals, sole traders and businesses across Melbourne’s west, including Werribee, Hoppers Crossing and Laverton.
If you want the extra time that comes with an agent, the step to take now is simple: get in touch before 31 October so we can add you to our client list. You do not need all your paperwork ready on day one.
Find out more about our tax return service or our work as a tax accountant in Melbourne, then book a time before 31 October.
Frequently asked questions
Is the deadline 31 October if I use an accountant?
Only if you are not on their client list by 31 October, or you had prior-year returns outstanding at 30 June 2026. Otherwise, most agent clients have until 15 May 2027, or 31 March 2027 if last year’s tax liability was $20,000 or more.
What happens if I miss 31 October by a few days?
The ATO generally warns you first and does not usually penalise isolated late lodgements. A penalty is possible, but it is generally not issued where the return results in a refund or a nil result.
I’m two years behind. Does the 15 May date apply to me?
No. With prior-year returns outstanding at 30 June 2026, your 2025-26 return is due 31 October 2026. That changes only if every outstanding return is lodged by 31 October 2026.
Do I have to pay by the lodgement date?
Not necessarily. For agent clients with a 15 May 2027 due date, the ATO staggers payment dates based on when the return is lodged: 21 March 2027 if lodged by 12 February 2027, 21 April 2027 if lodged between 13 February and 12 March 2027, and 5 June 2027 if lodged from 13 March 2027. For other due dates, payment generally follows your notice of assessment, so ask your agent.
Five tips before 31 October
- Check today whether any prior-year return is still outstanding.
- Changing agents? Tell the new one before 31 October.
- Check your agent on the Tax Practitioners Board register.
- Link your myGov account to the ATO so your agent can see your prefilled income.
- Owe money? Ask your agent how your lodgement date affects your payment date, because for 15 May clients, lodging earlier can bring your payment date forward.
This is general information only. Talk to a registered tax agent about your situation.
