Below is the full set of BAS due dates for FY2026-27 with both lodgement routes side-by-side. Three rules govern the gap between them. The dates are pulled directly from the ATO website and cross-checked against the FY27 calendar (28 February 2027 falls on a Sunday, which moves it to the next business day for everyone).
The full FY2026-27 schedule
* The standard Q2 due date is 28 February. In FY27 that falls on a Sunday, so the ATO moves the deadline to the next business day — Monday 1 March 2027 — for everyone.
Three rules that explain the table
Rule 1 — paper lodgement = the 28th of the month after the quarter ends
Q1 ends 30 September → due 28 October. Q3 ends 31 March → due 28 April. Q4 ends 30 June → due 28 July. Q2 is the odd one out because it ends 31 December and the ATO gives an extra month of breathing room over Christmas / January, so it's due 28 February instead of 28 January.
Rule 2 — online (self-lodge) adds two weeks
If you lodge through ATO Online Services for Business, myGov, or a SBR-enabled platform under your own credentials, the deadline shifts by two weeks. Q1 paper 28 Oct → online 11 Nov. Q3 paper 28 Apr → online 12 May. Q4 paper 28 Jul → online 11 Aug. The online concession is the ATO's nudge to encourage electronic lodgement.
Rule 3 — through a registered agent = roughly four extra weeks (except Q2)
Lodge through a registered tax or BAS agent and you pick up the agent concession on top: another two weeks beyond the online date. Q1 online 11 Nov → agent 25 Nov. Q3 online 12 May → agent 26 May. Q4 online 11 Aug → agent 25 Aug.
Q2 is the exception.The Christmas / January concession that pushes everyone's Q2 to 28 February uses up the extension already — there's no separate agent concession on top. Whether you lodge yourself or through us, Q2 is due 28 February (or 1 March 2027 specifically, because the 28th is a Sunday). Plan around that.
Q1 BAS — period 1 July to 30 September 2026
Q1 covers the first quarter of FY27. Self-lodgers on paper are due 28 October 2026 (Wednesday). Self-lodgers using ATO Online Services for Business, myGov, or a SBR-enabled platform are due 11 November 2026 (Wednesday). Lodge through us as your registered tax or BAS agent and the date moves to 25 November 2026 (Wednesday). Q1 is the easiest quarter to handle on time because the agent concession adds the full four weeks.
Q2 BAS — period 1 October to 31 December 2026
Q2 covers the October-December quarter and is the only quarter without an agent concession on top of the standard date. The standard due date is 28 February 2027, but in FY27 the 28th falls on a Sunday so the ATO rolls everyone's deadline to the next business day — Monday 1 March 2027. Self-lodger paper, self-lodger online, and lodging through a registered agent are all due 1 March 2027. The Christmas / January concession built into Q2 already absorbs the extra time the agent concession gives on the other quarters.
Q3 BAS — period 1 January to 31 March 2027
Q3 covers the January-March quarter — often searched as "the March BAS" or "Q3 BAS due date." Self-lodgers on paper are due 28 April 2027 (Wednesday). Online self-lodgers are due 12 May 2027 (Wednesday). Lodge through a registered tax or BAS agent and the date moves to 26 May 2027 (Wednesday). The agent concession gives you almost a full month of extra time for Q3 versus self-lodging on paper.
Q4 BAS — period 1 April to 30 June 2027
Q4 closes out the financial year and lands during the busy EOFY period. Self-lodger paper is due 28 July 2027 (Wednesday). Online self-lodgers are due 11 August 2027 (Wednesday). Through a registered agent the date moves to 25 August 2027 (Wednesday). Many businesses pair Q4 BAS with their annual tax return work — if you're on our lodgement program both pieces are scheduled together so figures reconcile cleanly.
Monthly BAS lodgers
If your turnover is $20 million or more, or you've elected monthly, the rule is simpler: the BAS for a given month is due on the 21st of the next month. There's no agent concession on monthly BAS — it's 21st whether you lodge yourself or through us. For FY27 that means:
- July 2026 BAS → due 21 August 2026 (Fri)
- August 2026 → due 21 September 2026 (Mon)
- September 2026 → due 21 October 2026 (Wed)
- October 2026 → due 23 November 2026 (Mon — 21st is Sat)
- November 2026 → due 21 December 2026 (Mon)
- December 2026 → due 21 January 2027 (Thu)
- January 2027 → due 22 February 2027 (Mon — 21st is Sun)
- February 2027 → due 22 March 2027 (Mon — 21st is Sun)
- March 2027 → due 21 April 2027 (Wed)
- April 2027 → due 21 May 2027 (Fri)
- May 2027 → due 22 June 2027 (Mon — 21st is Sun)
- June 2027 → due 21 July 2027 (Wed)
Same 21st rule each month, falls back to the next business day when it lands on a weekend or public holiday. The dates above already factor in those rolls for FY27.
Payment is due the same day as lodgement
A common misread: people lodge on time but pay late, thinking payment runs on a separate clock. It doesn't. Whatever date appears in the table above is both your lodgement deadline and your payment deadline. Late payment attracts the General Interest Charge (GIC), which from 1 July 2025 is no longer income-tax deductible — so a missed BAS payment now costs you twice (the interest + losing the deduction you used to get for it).
Annual GST returns
Voluntary GST registrations with no agent concession lodge an annual GST return. For FY27 (1 Jul 2026 – 30 Jun 2027) that's due by the same date as your income tax return — typically 31 October 2027 if self-lodging, or as scheduled by your registered agent if you're on our lodgement program.
If you miss a date
The ATO's standard penalty is a Failure-to-Lodge (FTL) fine, calculated per 28-day block of lateness, scaled by entity size (small / medium / significant global entity). For most small businesses it's currently $313 per 28-day block, capped at 5 blocks (so $1,565 maximum per BAS). The ATO usually waives the first FTL if you've had a clean lodgement history and you ring them. We typically handle that conversation for you if it ever comes up.
Frequently asked questions
Common BAS-due-date questions we get from clients and from search visitors:
When are BAS due dates in 2026?
For FY2026-27, the four quarterly BAS due dates are: Q1 (Jul-Sep 2026) due 28 October 2026 (paper) / 11 November 2026 (online) / 25 November 2026 (through a registered agent); Q2 (Oct-Dec 2026) due 1 March 2027 for everyone (the standard 28 February falls on a Sunday); Q3 (Jan-Mar 2027) due 28 April 2027 / 12 May 2027 / 26 May 2027; Q4 (Apr-Jun 2027) due 28 July 2027 / 11 August 2027 / 25 August 2027.
When is the Q3 BAS due (January-March quarter)?
The Q3 BAS for the period 1 January 2027 - 31 March 2027 is due 28 April 2027 if you self-lodge on paper, 12 May 2027 if you self-lodge online, or 26 May 2027 if you lodge through a registered tax or BAS agent.
When is the March BAS due?
The "March BAS" usually refers to the Q3 quarterly BAS covering January to March 2027, which is due 28 April 2027 (paper), 12 May 2027 (online), or 26 May 2027 (registered agent). If you're a monthly BAS lodger, the March 2027 monthly BAS is due 21 April 2027.
What are the monthly BAS due dates?
Monthly BAS lodgers (turnover $20m+ or elected monthly) lodge by the 21st of the following month. There is no agent concession for monthly BAS — the 21st rule applies whether you lodge yourself or through a registered agent. If the 21st is a weekend or public holiday, the deadline rolls to the next business day.
What's the difference between self-lodging BAS and using a tax agent for BAS?
Self-lodgers face the standard ATO due dates (28th of the month after each quarter for paper, +2 weeks for online). Lodging through a registered tax or BAS agent gives you the lodgment-program concession, which adds approximately 4 weeks to most quarterly deadlines (Q1, Q3, Q4). Q2 is the exception — the Christmas/January extension already in place means there's no separate agent concession on top.
What happens if you miss a BAS due date?
The ATO charges a Failure-to-Lodge (FTL) penalty per 28-day block of lateness, scaled by entity size. For most small businesses it's $313 per 28-day block, capped at five blocks ($1,565 maximum per BAS). The General Interest Charge (GIC) also applies on any unpaid amount; from 1 July 2025 GIC is no longer income-tax deductible. The first FTL is often waived if you have a clean lodgment history and call the ATO; we typically handle that conversation for clients.
Sources
Standard BAS due dates and the online lodgement concession: ATO — Due dates for lodging and paying your BAS.
Registered-agent quarterly concession dates: ATO Lodgment program — Quarterly activity statements (search "lodgment program quarterly activity statements" on ato.gov.au — the URL changes between site refreshes; the substantive concession does not).
FTL penalty schedule and current penalty unit value: ATO — Failure to lodge on time penalty.
GIC non-deductibility from 1 July 2025: Treasury Laws Amendment (Tax Incentives and Integrity) Act 2025, repealing s 25-5(1)(c) of the Income Tax Assessment Act 1997.