Australian Tax Deadlines: Every Date That Matters
When your return is due, how a tax agent changes the date, and what actually happens if you are late
Tax deadlines in Australia are fixed, published years in advance, and rarely move. Almost every late lodgement happens because someone did not know the date, not because they could not meet it. Here is the whole calendar in one place.
The income year is not the calendar year
Australia's income year runs 1 July to 30 June. When people say "FY 2025-26" they mean 1 July 2025 to 30 June 2026. This catches out anyone who has moved from a country on a calendar tax year — the United States, Canada, Germany and most of Europe all run 1 January to 31 December.
Everything else on this page hangs off that date. Your return covers income you received in that window, and deductions for expenses you incurred in that window.
31 October — the date that matters most
If you lodge your own return, it is due by 31 October following the end of the income year. So the year ending 30 June 2026 is due by 31 October 2026.
You can lodge from 1 July, but there is a good reason to wait a couple of weeks. Employers, banks and health funds report to the ATO directly, and that information pre-fills your return. Early in July it is usually incomplete; by late July most of it has landed. Lodging before your data is in is the most common cause of an amendment later.
Using a tax agent changes the deadline — but only if you act by 31 October
Registered tax agents have their own lodgement programme, and their clients generally get considerably longer — often through to May of the following year, depending on your circumstances and lodgement history.
The catch that surprises people: you must be on the agent's client list by 31 October to get the extension. Walking into an agent's office in February does not retrospectively grant you the later deadline. If you think you might use an agent, register with one before 31 October even if you are not ready to lodge.
Only a tax agent registered with the Tax Practitioners Board may charge a fee to prepare your return. You can check any agent's registration on the TPB public register before you engage them.
Quarterly BAS — a separate clock
If you are registered for GST, your Business Activity Statement runs on its own cycle, independent of your income tax return. The standard quarterly due dates are:
- Quarter 1 (July – September) — due 28 October
- Quarter 2 (October – December) — due 28 February
- Quarter 3 (January – March) — due 28 April
- Quarter 4 (April – June) — due 28 July
Quarter 2 gets a longer run because of the Christmas period. Lodging through a registered agent can extend some of these dates as well.
If your GST turnover is $20 million or more you report monthly, due on the 21st of the following month. Some smaller businesses report annually. If you are unsure which cycle applies to you, it is shown in your ATO online account.
PAYG instalments
If you earn business or investment income, the ATO may put you into the PAYG instalments system — paying tax during the year rather than in one bill afterwards. Instalments generally fall on the same quarterly dates as BAS, and if you lodge a BAS the instalment usually appears on it.
This is not an extra tax. It is the same tax, paid earlier and in smaller pieces. The amount is credited against your final assessment.
What late lodgement actually costs
The ATO applies a Failure To Lodge penalty. It works in units: one penalty unit for every 28 days (or part thereof) that a return is late, capped at five units. Larger entities pay a multiple of that base amount.
We have deliberately not printed a dollar figure here. The value of a penalty unit is indexed and changes periodically, and a stale number on a tax page is worse than no number — check the current value on the ATO website.
Two things worth knowing. First, the ATO frequently does not apply the penalty for a first offence, particularly where a refund is owed and you lodge without being chased. Second, interest accrues separately on unpaid tax, and that is not discretionary. If you owe money, lodging late is the expensive part, but paying late is the part that compounds.
If you genuinely cannot lodge on time, contact the ATO before the deadline rather than after. Deferrals exist and are far easier to obtain in advance.
Keep your records for five years
Records supporting a claim must be kept for five years from the date you lodge, not five years from the expense. A receipt for a tool bought in July 2025, claimed in a return lodged October 2026, needs to survive until October 2031.
This is the requirement that quietly defeats the shoebox. Thermal receipts fade badly inside twelve months, let alone five years, and a receipt you cannot read is a claim you cannot substantiate. A photograph taken when the receipt is fresh satisfies the requirement — the ATO accepts a clear digital copy.
The calendar, in one place
| Date | What is due |
|---|---|
| 1 July | Income year starts; lodgement opens (wait for pre-fill) |
| 28 July | Q4 BAS (April – June) |
| 28 October | Q1 BAS (July – September) |
| 31 October | Tax return due if self-lodging; last day to register with an agent for the extension |
| 28 February | Q2 BAS (October – December) |
| 28 April | Q3 BAS (January – March) |
| 30 June | Income year ends |
Making the date a non-event
The reason 31 October feels stressful is almost never the lodgement itself — it is reconstructing a year of records in the fortnight beforehand. Capture expenses as they happen and the deadline becomes an afternoon rather than a scramble.
That is precisely what TaxBot is for: photograph a receipt when you get it, and it is categorised, dated into the right financial year, and waiting for you in July.
