Missed the 31 October tax deadline? What happens next

If you do your own tax return, the deadline for your 2026 tax return is almost here. It's normally 31 October. This year that date falls on a Saturday, so the ATO gives self-lodgers until the next business day, Monday 2 November 2026. Here's what happens if you miss it, and how to get more time if you need it.

Why this year's deadline is different

When 31 October lands on a weekend, the due date for lodging your own return moves to the next business day. That gives you two extra days to lodge through myTax.

There is a catch if you would rather hand your return to a professional. Most registered tax agents have a lodgment program that lets them lodge returns for their clients after 31 October. To be covered by it, you have to be on the agent's client list by 31 October. The ATO has told agents that the weekend doesn't move that date in 2026. If you call an agent on Monday 2 November, you're too late for their program.

Want more time? Get on a registered tax agent's client list by Saturday 31 October, not the Monday after.

Who this applies to

This applies to anyone lodging their own 2025-26 return, whether online through myTax or on paper. If you already use a tax agent, your due date is set by their lodgment program and depends on your circumstances, so check with them.

There is one group who can't rely on an agent for extra time. If you had any tax return still outstanding on 30 June 2026, your 2026 return is due by 31 October, even through an agent. This applies to any earlier year, not only last year. The good news is that if you lodge all of those older returns by 31 October, your 2026 return goes back to the agent's normal due date.

What happens if you lodge late

The ATO can apply a failure to lodge on time penalty. It works like this:

• One penalty unit for every 28 days, or part of 28 days, that your return is late.
• A penalty unit is $364 for anything due on or after 1 July 2026.
• The penalty is capped at 5 units, which is $1,820 for individuals and small businesses.
• Larger businesses pay 2 or 5 times as much, depending on their size.

The ATO doesn't hand these out automatically. It says it generally doesn't apply penalties for isolated late lodgments, and it will warn you by phone or in writing before it applies one. It also generally won't issue a late lodgment penalty if your return results in a refund or a nil amount.

Tax you owe is a separate matter. If you lodge your own return and end up with a tax bill, payment is due by 21 November. Interest can apply to anything still unpaid after that date, and neither interest nor penalties are tax deductible.

If you do receive a penalty, you can ask the ATO to remit it. You'll need to lodge the overdue return first and explain what stopped you from lodging on time.

Common mistakes to avoid

These are the slip-ups we see most around the deadline:

• Assuming the weekend also gives you until Monday to sign up with a tax agent. It doesn't.
• Leaving it late because you're expecting a refund. You can't get your money back until you lodge.
• Forgetting about an older return. One missing year can bring this year's due date back to 31 October.
• Ignoring a letter or call from the ATO. That warning is your chance to lodge before a penalty applies.
• Rushing and accepting pre-filled figures without checking them against your own records.

A worked example

Daniel and Sam are flatmates who both usually lodge their own returns. Both are running behind this year.

Daniel contacts a registered tax agent on Tuesday 27 October and is added to their client list that week. His return is now covered by the agent's lodgment program, so his due date will usually be well after 2 November.

Sam waits until Monday 2 November to call an agent. That's too late for the lodgment program, so Sam's return is still due that day. Sam finally lodges on 10 December, 38 days late. That's two 28-day periods, so Sam could face a penalty of two units, or $728. Sam also owes $900 in tax, which was due on 21 November, so interest can apply from that date until it's paid.

One phone call a week earlier would have saved Sam the risk, the interest and the worry.

Self-lodgers have until Monday 2 November, but to use a tax agent you need to sign up by Saturday 31 October.

Key Takeaways