When is the quarterly BAS due?

28 October for July to September, 28 February for October to December, 28 April for January to March and 28 July for April to June. For 2026–27 the October to December BAS falls due on Sunday 28 February 2027, so you can lodge and pay on Monday 1 March. Lodging online yourself can add two weeks to every quarter except October to December.

When is the monthly BAS due?

On the 21st of the following month: the July BAS is due 21 August, the August BAS 21 September, and so on. When the 21st falls on a weekend or public holiday, lodge and pay on the next business day. Monthly reporters don't get the two-week online concession.

What are the BAS due dates if I use a tax agent?

Registered tax and BAS agents lodging electronically get later dates for 2026–27 quarterly BAS: 25 November 2026 for July to September, 28 February 2027 for October to December (no extra time), 26 May 2027 for January to March and 25 August 2027 for April to June. Your previous BAS must have been lodged electronically to qualify.

What is the two-week BAS extension for lodging online?

If you lodge your quarterly BAS online yourself, through ATO online services or business software, you may get two extra weeks to lodge and pay: 11 November instead of 28 October, 12 May instead of 28 April and 11 August instead of 28 July. It doesn't apply to the October to December quarter, which already has an extra month, or to monthly BAS.

When is the annual GST return due?

31 October after the end of the financial year, or 28 February if you don't have to lodge an income tax return. The 2026–27 annual GST return is due 31 October 2027, a Sunday, so you can lodge on Monday 1 November. If a tax agent lodges it, it's usually due with your income tax return.

What happens if I lodge my BAS late?

The ATO can charge a failure-to-lodge penalty of one penalty unit, A$364 from 1 July 2026, for each 28 days or part of 28 days the BAS is late, up to five units (A$1,820) for a small business. Medium and large businesses pay two or five times as much. The general interest charge applies to late payments, and since 1 July 2025 it isn't tax-deductible.

BAS Due Dates 2026–27: Quarterly, Monthly, Annual

Short answer: a quarterly BAS is due on the 28th of the month after the quarter, except October–December, which is due 28 February. Lodge online yourself and you may get two extra weeks on the other three quarters. A monthly BAS is due on the 21st of the following month. A registered tax or BAS agent gets about four weeks more. When a due date falls on a weekend or public holiday, lodge and pay on the next business day, as with Sunday 28 February 2027.

These are the 2026–27 dates (1 July 2026 to 30 June 2027), current as of 12 November 2026. Not registered yet? See how to register for GST.

Quarterly BAS due dates 2026–27

Quarter	Lodging yourself	Online two-week concession	Through a tax or BAS agent
Q1: July–September 2026	Wed 28 October 2026	Wed 11 November 2026	Wed 25 November 2026
Q2: October–December 2026	Mon 1 March 2027 (28 February is a Sunday)	No extension	Mon 1 March 2027 (no extension)
Q3: January–March 2027	Wed 28 April 2027	Wed 12 May 2027	Wed 26 May 2027
Q4: April–June 2027	Wed 28 July 2027	Wed 11 August 2027	Wed 25 August 2027 (to be confirmed)

The payment is due on the same day as the lodgment. The October–December quarter has no extra time on any route, because its 28 February date already includes a one-month extension over Christmas. The ATO marks the Q4 agent date as to be confirmed in the 2027–28 lodgment program.

Still finishing 2025–26? The April–June 2026 BAS was due 28 July 2026, or 25 August 2026 through an agent.

Monthly BAS due dates 2026–27

Businesses with GST turnover of A$20 million or more must report GST monthly, and smaller businesses can choose to (exporters often do, to get refunds sooner). A monthly BAS is due on the 21st of the following month:

Month	Due
July 2026	Fri 21 August 2026
August 2026	Mon 21 September 2026
September 2026	Wed 21 October 2026
October 2026	Mon 23 November 2026 (21st is a Saturday)
November 2026	Mon 21 December 2026
December 2026	Thu 21 January 2027 (agents: Mon 22 February 2027 for businesses up to A$10 million)
January 2027	Mon 22 February 2027 (21st is a Sunday)
February 2027	Mon 22 March 2027 (21st is a Sunday)
March 2027	Wed 21 April 2027
April 2027	Fri 21 May 2027
May 2027	Mon 21 June 2027
June 2027	Wed 21 July 2027

Monthly reporters don’t get the two-week online concession. The only agent extension is for the December BAS: 21 February instead of 21 January, for businesses with turnover up to A$10 million that lodge electronically through a registered agent. Public holidays in your state can also move a date to the next business day.

Annual GST return

You can report GST once a year if you’re voluntarily registered and your GST turnover is under A$75,000 (A$150,000 for non-profits), or if you pay GST instalments.

Financial year	Due
2025–26	Mon 2 November 2026 (31 October was a Saturday)
2026–27	Mon 1 November 2027 (31 October is a Sunday)

If you don’t have to lodge an income tax return, the annual GST return is due 28 February instead. Through a tax agent, it’s usually due with your income tax return. You still pay any GST instalments the ATO sets each quarter.

The two-week online concession

Lodge your quarterly BAS online yourself and you may get two extra weeks to lodge and pay:

Who: businesses lodging their own quarterly BAS through ATO online services (myGov for sole traders, Online services for business) or software that lodges directly with the ATO.
Which quarters: July–September, January–March and April–June. Not October–December.
Not for: monthly BAS, paper lodgment, or BAS lodged through an agent (agents have their own dates).

The ATO publishes the full terms and conditions. If you’re not sure you qualify, lodge by the 28th.

Tax and BAS agent dates

Registered tax and BAS agents work to the ATO’s lodgment program, which gives later dates for quarterly BAS lodged electronically:

Quarter	Standard date	Agent date (2026–27)
Q4 2025–26: April–June 2026	28 July 2026	25 August 2026
Q1: July–September 2026	28 October 2026	25 November 2026
Q2: October–December 2026	28 February 2027	28 February 2027 (moves to 1 March)
Q3: January–March 2027	28 April 2027	26 May 2027
Q4: April–June 2027	28 July 2027	25 August 2027 (to be confirmed)

To get the agent dates, your previous BAS must have been lodged electronically. Your first BAS, or one after a paper lodgment, may be due on the standard date. Payments for GST and PAYG instalment notices (forms R, S and T) stay on the standard dates.

Worked example: a Perth skincare brand’s year

Cottesloe Botanics sells skincare on Shopify and Amazon Australia, with about A$310,000 of sales a year. It’s registered for GST, reports quarterly and lodges its own BAS online with Xero.

Quarter	GST on sales (1A)	GST on purchases (1B)	Pays	Lodges and pays by
July–September 2026	A$6,940	A$2,310	A$4,630	11 November 2026 (two-week concession)
October–December 2026	A$9,870	A$3,920	A$5,950	1 March 2027 (no extension)
January–March 2027	A$5,820	A$1,960	A$3,860	12 May 2027
April–June 2027	A$6,410	A$2,780	A$3,630	11 August 2027

The Christmas quarter is its biggest, and its only fixed date. If it handed its BAS to a BAS agent, the July–September quarter would move to 25 November.

Late lodgment: penalties and interest

	Small business	Medium (GST turnover A$1 million to under A$20 million)	Large
Penalty per 28 days late	A$364	A$728	A$1,820
Maximum (5 periods)	A$1,820	A$3,640	A$9,100

These use the penalty unit value of A$364 for lodgments due from 1 July 2026 (it was A$330 before). The ATO often remits the penalty for a small business with a good record that lodges as soon as it can, so lodge even if you can’t pay. Unpaid amounts attract the general interest charge, which is calculated daily and, since 1 July 2025, is no longer tax-deductible. If you can’t pay on time, lodge anyway and set up a payment plan in ATO online services.

Official sources

Due dates for lodging and paying your BAS, Australian Taxation Office
BAS agent lodgment program 2026–27, Australian Taxation Office
Registered agent lodgment program: activity statements, Australian Taxation Office
Lodging your BAS or annual GST return, Australian Taxation Office
Penalty units, Australian Taxation Office