Quarterly BAS due dates for 2026–27 are 28 October 2026 (July–September), 28 February 2027 (October–December), 28 April 2027 (January–March) and 28 July 2027 (April–June). Your October quarter BAS is due Wednesday 28 October 2026 if you lodge yourself. Eligible online lodgers may get two extra weeks, and eligible clients of a registered BAS agent may have until 25 November 2026. The date printed on your BAS is the one that counts.
That is the short answer. The rest of this guide explains which date applies to you, why the December quarter works differently, what changed for super now Payday Super has started, and how to get your Q1 BAS lodged without a last-minute scramble.
Girl Friday Australia is a registered BAS agent, Xero Certified Advisor and Xero Gold Partner. We prepare and lodge BAS and IAS for small businesses, sole traders and tradies Australia-wide. All dates below come from the ATO, and we link to the source pages so you can check them yourself.
When is the October 2026 BAS due?
The quarter 1 BAS for 1 July to 30 September 2026 has an original due date of 28 October 2026 for lodgement and payment. That is the standard date for quarterly lodgers, per the ATO’s due dates for lodging and paying your BAS page.
There are three ways that date can move for this quarter:
- Lodging on paper: 28 October 2026. No extension.
- Lodging yourself online (eligible): an extra two weeks, which takes you to 11 November 2026. The ATO applies this automatically to eligible quarterly statements. You don’t need to apply.
- Lodging through a registered BAS or tax agent (eligible): 25 November 2026 under the ATO’s BAS agent lodgment program 2026–27.
If you already use an agent, your agent should know which date applies to you. If you’re not sure, check the due date on the activity statement in ATO online services or ask us.
What are all the BAS due dates for 2026–27?
Here are the quarterly dates for the 2026–27 financial year, taken from the ATO’s BAS due-date page, the ATO’s two-week lodgment concession terms and the BAS agent lodgment program:
Quarter 1: July to September 2026
- Original due date: 28 October 2026
- Eligible online self-lodgers: two weeks later (11 November 2026)
- Eligible clients of a registered agent: 25 November 2026
Quarter 2: October to December 2026
- Original due date: 28 February 2027. That falls on a Sunday, so under the ATO’s weekend rule you have until the next business day, Monday 1 March 2027.
- No extra online or agent concession. The ATO says this quarter already includes a one-month extension.
Quarter 3: January to March 2027
- Original due date: 28 April 2027
- Eligible online self-lodgers: two weeks later (12 May 2027)
- Eligible clients of a registered agent: 26 May 2027
Quarter 4: April to June 2027
- Original due date: 28 July 2027
- Eligible online self-lodgers: two weeks later (11 August 2027)
- Eligible clients of a registered agent: 25 August 2027. The ATO lists this date as still to be confirmed when the 2027–28 program is developed.
Monthly BAS is due on the 21st of the following month. For example, the September 2026 monthly BAS is due 21 October 2026. Standard monthly statements don’t get the agent concession. The exception is the December monthly BAS: it’s due 21 January, but eligible business clients with turnover up to $10 million who report GST monthly and lodge electronically through a registered agent have until 21 February.
Annual GST returns (for businesses voluntarily registered for GST with GST turnover under $75,000) are generally due 31 October. If you use a registered agent, a different date may apply.
Do I lodge BAS monthly, quarterly or annually?
Most small businesses lodge quarterly. According to the ATO:
- You must report monthly if your GST turnover is $20 million or more, or if the ATO has told you to.
- You report quarterly if your GST turnover is under $20 million and the ATO hasn’t told you to report monthly.
- You can choose monthly reporting under $20 million. Some businesses do this for smaller, more regular payments and tighter record keeping.
- You can lodge annually if you’re voluntarily registered for GST and your GST turnover is under $75,000 ($150,000 for not-for-profits).
If you want to change your cycle, the ATO says you can generally start straight away if you change early in the period. Otherwise the change takes effect from the next quarter or year. Sole traders need to phone the ATO or apply in writing. A registered agent can request the change for other entities through Online services for agents.
Who gets the extra two weeks for lodging online?
The ATO’s two-week concession applies if you receive and lodge your quarterly activity statements online. It covers quarters 1, 3 and 4. It’s ongoing, you don’t need to apply, and the new due date shows on your statement once it generates.
The ATO says the concession doesn’t apply to:
- monthly activity statements
- monthly GST payers who also have quarterly PAYG instalments or other quarterly roles
- quarterly PAYG instalments for head companies of consolidated groups
- large business clients with substituted accounting periods
- anyone whose original due date isn’t the 28th of the month
Plain-English tip: if you lodge through Xero or MYOB under your own credentials, that’s online lodgement. Paper lodgement loses the concession.
How does the BAS agent lodgment program work?
The BAS agent lodgment program gives eligible clients of registered agents later lodgement and payment dates for quarterly activity statements lodged electronically through Online services for agents or the Practitioner Lodgment Service. For 2026–27, that means 25 November 2026 for Q1 and 26 May 2027 for Q3.
A few conditions matter. The ATO applies program dates to eligible statements that generate after the agent has lodged your previous activity statement electronically. If this is your first activity statement, or your last one was lodged on paper, an earlier due date may apply. That’s why it pays to set up your agent well before quarter-end, not the night before 28 October.
The concession changes when you lodge and pay. It doesn’t change what you owe. Your GST and PAYG amounts are exactly the same, and you still need accurate books behind them.
Want your Q1 BAS off your plate? Girl Friday lodges BAS & IAS from $180 per quarter. We’re a registered BAS agent with no lock-in contracts, and we reply within one business day. Get a free quote or book a discovery call.
Is super still due on 28 October?
No, not for the July to September 2026 quarter. From 1 July 2026, Payday Super means employers must pay super guarantee for each payday. Contributions must be received by the employee’s fund within 7 business days after payday, with some exceptions such as new employees. The old quarterly super dates (28 October, 28 January, 28 April and 28 July) applied before 1 July 2026. Source: ATO, About Payday Super.
So 28 October is still a big day for your BAS, but it’s no longer your super catch-up day. The ATO also notes that super guarantee is now calculated on qualifying earnings and reported through STP, and that the Small Business Superannuation Clearing House has closed. If your payroll isn’t set up for this yet, read our guide to Payday Super in Xero.
What goes on my October quarter BAS?
Your BAS reports the tax obligations registered for your business. For most small businesses, that means some or all of:
- GST: GST on sales (1A) and GST credits on purchases (1B), based on correctly coded transactions
- PAYG withholding: amounts withheld from wages paid to employees during the quarter
- PAYG instalments: if the ATO has put you in the instalment system
- Fuel tax credits: if you’re registered and eligible
- Other obligations such as FBT instalments, luxury car tax or wine equalisation tax, where they apply
If you only have PAYG withholding or instalments and aren’t registered for GST, you may receive an instalment activity statement (IAS) instead.
How do I get my Q1 BAS ready before the deadline?
The deadline is rarely the problem. Messy books are. Here’s the order we work in for clients:
- Reconcile every bank and card account to 30 September 2026. Unreconciled lines are where wrong GST hides.
- Check GST coding on unusual transactions, such as insurance, bank fees, overseas subscriptions, private use and asset purchases.
- Clear the suspense or “ask my accountant” account so nothing’s left unallocated.
- Tie payroll to STP. Wages and PAYG withheld on the BAS should match what payroll reported for July–September.
- Review the GST report or activity statement in Xero or MYOB against the prior quarter. Big swings need an explanation.
- Lodge and pay by your correct date, then save the lodgement receipt and payment reference.
For a step-by-step walkthrough, see how to prepare and lodge your BAS in Xero.
What if I can’t lodge or pay my BAS on time?
Lodge anyway, and talk to the ATO early. The ATO’s guidance is to contact them or your registered tax professional before the due date if you’re struggling. Late payment attracts the general interest charge (GIC). If you owe $200,000 or less, you may be able to set up a payment plan through ATO online services.
Lodging on time, even if you can’t pay in full, keeps the ATO seeing an accurate picture and keeps your options open. If you’re several quarters behind, our catch-up bookkeeping guide walks through the shame-free fix. If tax debt is already building, read ATO tax debt in 2026.
This guide covers BAS lodgement and bookkeeping. For income-tax planning or objections, speak to your registered tax agent or accountant.
Frequently asked questions
Is the Q1 BAS due on 28 October or 25 November 2026?
28 October 2026 is the original due date. 25 November 2026 only applies if you’re eligible under the BAS agent lodgment program and a registered agent lodges electronically for you. Eligible self-lodgers who lodge online get two extra weeks instead. Always check the date shown on your statement.
Does the December quarter BAS get an extension?
No extra concession applies. The ATO says the 28 February due date already includes a one-month extension. In 2027, 28 February is a Sunday, so the ATO’s next-business-day rule gives you until Monday 1 March 2027.
What happens if a BAS due date falls on a weekend?
The ATO says that if the due date is on a weekend or public holiday, you have until the next business day to lodge and pay.
Can I lodge my BAS early?
Yes. Once the quarter has ended and your books are reconciled, you can lodge. The ATO also lets you make early payments towards future BAS liabilities.
Do sole traders have different BAS due dates?
No. The same monthly, quarterly and annual rules apply based on your GST turnover and reporting cycle. Sole traders can lodge through myGov-linked ATO online services, or use a registered BAS agent.
Does using a BAS agent reduce the GST I pay?
No. Agent concessions change the due date, not the amount. What an agent adds is a review of your coding and reconciliations so the amount is right the first time.
Get your October BAS sorted
You don’t need perfect books before you reach out. Send us what you have, whether that’s a Xero or MYOB login, your last BAS or a shoebox of receipts. We’ll tell you honestly what it takes to lodge on time.
- Get a free quote → girlfridayaustralia.com/quote
- Book a discovery call → girlfridayaustralia.com/contact
- Call 0404 877 436 or email info@girlfridayaustralia.com (Mon–Fri 9am–5pm AEST)
See our BAS & IAS services for what’s included. Done right, every time, with no jargon, no judgement and no lock-in.