Tax Return Deadline 2026: Is Your Tax Return Due on 31 October?

If your 2025–26 tax return is still sitting somewhere on the mental to-do list, October is probably the month to move it a little closer to the top.

For most people who prepare and lodge their own tax return, 31 October 2026 is the deadline. If you use a registered tax agent, like Citrine Advisory, you may be eligible for a later lodgment date, but there is an important catch that is worth knowing before October disappears.

You generally need to engage your registered tax agent before 31 October.

So, if you've been meaning to sort your tax return and haven't quite got there yet, here's what you actually need to know.

When is the 2026 tax return deadline?

If you're lodging your own 2025–26 individual tax return, the standard deadline is 31 October.

The ATO says that if you're using a registered tax agent, they will generally have a special lodgment schedule that allows them to lodge returns for clients later than 31 October. To access the applicable tax-agent lodgment arrangements, you generally need to engage your tax agent before the 31 October deadline.

There can be exceptions depending on your circumstances, particularly if you have overdue returns from previous years, so it's worth checking rather than assuming you've automatically got extra time.

You can read the ATO's current guidance on lodging your tax return and due dates.

What if I haven't chosen an accountant yet?

If you've been planning to use an accountant for your 2025–26 tax return but haven't actually contacted one yet, now is a good time to do it.

Waiting until November and then deciding to find an accountant doesn't necessarily mean you'll receive the later lodgment date that can apply under the tax-agent program. The ATO specifically says you need to engage a registered tax agent before 31 October.

If you're looking for a Melbourne accountant who can help with tax and tax planning, Citrine works with individuals, families, high-income earners and business owners, so your relationship with your accountant doesn't have to begin and end with lodging one return.

What happens if I miss the 31 October tax deadline?

First of all, don't ignore it because you think you've already missed your chance.

The ATO's advice is to lodge as soon as possible if you miss your due date. If you're expecting a tax bill, delaying the return can make matters worse because payment dates and interest can also come into the picture.

If you have older outstanding tax returns as well, it's worth getting those looked at at the same time. Previous overdue returns can affect the lodgment dates available to you through a tax agent, so this is one of those situations where it's better to know exactly where you stand rather than keep putting it off.

What do I need to get my tax return done?

What you'll need will depend on what happened during the financial year.

For someone with relatively straightforward employment income, a lot of information may already be available to the ATO through pre-fill, including employment income and bank interest. You still need to check that information is correct and make sure anything missing is added.

If you've got investments, shares, a rental property, capital gains, business income or other income sources, there can obviously be a little more involved. The same goes for deductions. Rather than trying to remember everything at the last minute, it's worth getting your records together and making sure you're actually claiming what you're entitled to.

If you've been trying to work out what the numbers mean for you this year, our guide to Australian tax brackets for 2026–27 is also a useful place to start.

Your tax return and tax planning aren't quite the same thing

This is something we're pretty passionate about at Citrine.

Preparing a tax return is largely looking backwards. We're working with income you've already earned, expenses you've already paid and decisions you've already made.

Tax planning is different because we're having those conversations while there's still time to actually do something.

If you're a higher-income earner, have investments, run a business or your financial situation is becoming more complicated, we'd much rather talk to you throughout the year than meet for the first time when everything has already happened.

We've written more about this in Planning Ahead vs Reacting in June, because good tax advice shouldn't only happen when a deadline is looming.

You can also find more practical tax and business information in the Citrine Knowledge Hub.

Still haven't done your 2025–26 tax return?

If you're planning to lodge your own return, 31 October 2026 is the date to have in your calendar.

If you'd rather use a registered tax agent, don't wait until the deadline has already passed to make contact. Getting in touch before 31 October gives your accountant the opportunity to check your circumstances, get you properly set up as a client and confirm the lodgment date that applies to you.

At Citrine Advisory, we help individuals, families, high-income earners and business owners with tax returns, tax planning and the bigger financial picture behind them.

If your 2025–26 tax return is still sitting on the list, come and have a chat with us before 31 October.

Let's get it sorted.

The information in this article is general in nature and doesn't take into account your individual circumstances. Tax lodgment dates can vary depending on your circumstances, including previous lodgment history, so please seek advice specific to your situation.