If I use a tax agent, do I really get until 15 May to lodge?

Someone at work told you there's no rush — put it through an accountant and you have until May. Someone else lodged their own return in July and had the refund three weeks later. It's now mid-August, you haven't started, and both of those people sound right. The extension does exist. What rarely gets explained is that it comes with conditions you either already meet or already don't, and that which date applies to you was effectively settled on 30 June.

The default date, and what actually shifts it

If you lodge your own return, the due date is 31 October. That is the rule for every individual who doesn't go through a registered tax agent. Where 31 October falls on a weekend, the due date rolls to the next business day after it — and 31 October 2026 is a Saturday, so self-lodgers reach the following Monday, 2 November. That is a rounding, not a plan.

Registered tax agents run a separate lodgment program, and that is what the 'until May' story is really about. The ATO's instruction for getting inside it is plain: if you're using a tax agent for the first time, or changing agents, contact them before 31 October to be part of their lodgment program. Engaging someone on 30 October is legal and close to useless — nobody prepares a return properly in a day, and an extension only helps if there is someone on the other end with time to use it.

Three dates, not one

Under the agent lodgment program, individuals do not share a single due date. As set out by the ATO as at 1 July 2026, the split works like this.

Your return is due 31 October 2026 — no extension at all — if one or more of your prior year tax returns was outstanding as at 30 June 2026. Being on an agent's books changes nothing here. This is the most common reason people are caught out: the extension rewards being up to date, it is not a way to catch up.

It is due 31 March 2027 if your latest lodged return resulted in a tax liability of $20,000 or more.

It is 15 May 2027 for everyone else — all remaining individuals not required to lodge earlier, including new registrations. A concession also allows returns due 15 May to be lodged by 5 June without penalty, provided any payment required is made by that date too.

So 'until May' is accurate for a large group and simply wrong for two smaller ones, and which group you are in was determined by facts that existed on 30 June 2026.

Lodging later does not mean paying later

This is the part that costs people money. If you lodge your own return between 1 July and 31 October and it produces a bill, payment is due by 21 November. If you lodge late, the payment due date is still 21 November, and interest can apply to any amount owing after that. Delay buys nothing on the payment side — it only removes the weeks you would have had to prepare for the number.

Through an agent it works differently again. For individuals whose lodgment due date is 15 May 2027, payment dates are staggered according to when the return is actually lodged: lodged up to and including 12 February 2027, payment is due 21 March 2027; lodged between 13 February and 12 March 2027, payment is due 21 April 2027; lodged from 13 March 2027, payment is due 5 June 2027.

What lodging late actually costs

The failure to lodge on time penalty is calculated at one penalty unit for every 28 days, or part of 28 days, that a document is overdue, up to a maximum of five penalty units. A penalty unit is $364 where the infringement occurs on or after 1 July 2026, which puts the ceiling for an individual at $1,820.

The ATO also says it generally will not issue a failure to lodge penalty notice for a late-lodged tax return where the lodgment results in a refund or a nil result — with exceptions, including where the penalty was applied before the return was lodged. Worth knowing, but a poor thing to rely on: you don't know whether you're in refund or in debt until the return is prepared, which is the step you haven't taken yet.

The general version, current as at August 2026: the useful work in August is not lodging — it is finding out which date is yours. Check whether any earlier year is still unlodged, because that single fact decides whether you have until 2027 or until this October. If you want to sit inside an agent's program, be on their client list well before 31 October rather than in the last week of it, and check the agent is registered by searching the Tax Practitioners Board register. If you're expecting a refund there is no reason to hold on to it. If you're expecting a bill, preparing early gives you the number without moving the date you have to pay it.

This is general information rather than advice about your own position — your due date depends on your lodgment history and your last assessment. Our income tax calculator will give you a rough sense of where FY 2026–27 leaves you, and getting a return prepared and lodged inside the program is what our individual tax return service is for.