When Are BAS Due Dates for Quarterly Lodgers?

Quarterly BAS due dates for 2026-27

If your GST turnover is under $20 million and the ATO has not told you to report monthly, you can lodge your BAS quarterly. The standard due dates are the same every year: 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.

The October to December quarter is due later than the others because its February date already includes a one-month extension over the Christmas period. That is also why it has no further agent or online extension.

• July to September 2026: due Wednesday 28 October 2026
• October to December 2026: due 28 February 2027, a Sunday, so Monday 1 March 2027
• January to March 2027: due Wednesday 28 April 2027
• April to June 2027: due Wednesday 28 July 2027

BAS agent and tax agent extensions

If a registered BAS or tax agent lodges for you electronically, the ATO's BAS agent lodgment program usually gives extra time. For 2026-27 the concession dates are 25 November 2026 for the July to September quarter and 26 May 2027 for the January to March quarter. The October to December quarter has no concession. For the April to June 2027 quarter the agent date is usually late August, and the ATO will confirm it later, so check it with your agent.

The concession has conditions. The agent must lodge through the ATO's online services for agents or practitioner lodgment service, and your previous activity statement must have been lodged electronically. If it is your first BAS, or your last one was lodged on paper, an earlier due date may apply.

If you lodge online yourself rather than through an agent, the ATO says you may be eligible for an extra 2 weeks to lodge and pay quarterly BAS. Again, this does not apply to the October to December quarter.

Monthly and annual BAS due dates

Monthly BAS is due on the 21st day of the month after the reporting period, so the July BAS is due on 21 August. Monthly reporting is compulsory if your GST turnover is $20 million or more, or if the ATO has directed you to report monthly. Businesses under $20 million can choose it, which some do to claim GST refunds sooner.

Standard monthly BAS does not get the agent concession. The exception is the December monthly BAS, which is due 21 January with an agent date of 21 February 2027 for businesses with turnover up to $10 million that report GST monthly and lodge electronically through an agent.

If you are voluntarily registered for GST with GST turnover under $75,000, or under $150,000 for a not-for-profit, you may report GST annually. The annual GST return is due 31 October, or 28 February after the year if you do not have to lodge an income tax return.

What if the due date falls on a weekend or public holiday?

If a BAS due date falls on a Saturday, Sunday or public holiday, you can lodge and pay on the next business day without penalty. In 2026-27 this matters for the October to December quarter: 28 February 2027 is a Sunday, so the BAS can be lodged and paid on Monday 1 March 2027.

The due date covers both lodgment and payment. Lodging on time but paying late still attracts the general interest charge on the unpaid amount, so if you cannot pay in full, lodge on time anyway and talk to the ATO about a payment plan.

When to get help

The agent concession is often worth four extra weeks of cash flow on three of the four quarters, provided the books are ready and lodgment stays electronic. It only helps if the bookkeeping is up to date before the original due date comes around.

If you are behind on BAS lodgments, catching up before the ATO takes action is usually the cheaper path. Acquire Strategic Accounting's BAS and bookkeeping team in Brisbane lodges BAS as a registered agent.