BAS due dates for 2026–27, and how to plan cash around each one

For many small businesses, the BAS is the single largest regular payment that isn’t wages. It arrives four times a year (or twelve, for monthly lodgers), it’s non-negotiable, and it’s made up largely of money that was never really the business’s to spend: GST collected from customers and tax withheld from employees’ pay.

The businesses that find BAS stressful are almost always the ones that treat it as an event. The ones that don’t are the ones that treat it as a routine. This guide gives you the 2026–27 calendar, explains the ATO’s timing rules, and sets out a simple routine for funding each BAS before it arrives — plus what to do when one lands at a bad time.

What are the BAS due dates for 2026–27?

The ATO lists these standard due dates for lodging and paying quarterly BAS:

Quarter	Period	Standard due date	Day
1	July – September 2026	28 October 2026	Wednesday
2	October – December 2026	28 February 2027	Sunday — next business day applies
3	January – March 2027	28 April 2027	Wednesday
4	April – June 2027	28 July 2027	Wednesday

For monthly BAS, the ATO says the due date is the 21st day of the month following the end of the reporting period.

The ATO’s weekend rule: if the due date is on a weekend or public holiday, you have until the next business day to lodge and pay. So the quarter 2 payment falls due on Monday 1 March 2027. Monthly due dates move in the same way — for example, 21 November 2026 is a Saturday.

Can you get more time?

Possibly. The ATO says that if you lodge online you may be eligible for an extra two weeks to lodge and pay your quarterly BAS, and that you may also get extra time if you lodge through a registered tax or BAS agent. The later date doesn’t apply to quarter 2, because its due date already includes a one-month extension.

Two cautions:

• Eligibility isn’t automatic in every case. Confirm your own due dates in ATO online services or with your agent.
• Extra time to pay isn’t extra money. It helps only if you use the time well.

What actually goes into your BAS bill?

Depending on your registrations, a BAS can include:

• GST collected on sales, less GST credits on purchases;
• PAYG withholding from employees’ wages;
• PAYG instalments towards income tax;
• other items such as fuel tax credits or wine equalisation tax, where relevant.

The first two are the ones to watch. GST and PAYG withholding are, in effect, held on behalf of others. And they matter personally for company directors: the ATO’s director penalty regime can make directors personally liable for unpaid PAYG withholding, GST and super guarantee charge.

How do you fund every BAS without the scramble?

The single most effective habit is simple: move the BAS money out of your operating account every week.

1. Open a separate business account for tax, kept apart from day-to-day spending.
2. Each week, transfer the GST collected (net of credits) and the PAYG withheld from that week’s wages. Your accounting software or BAS agent can give you the running figure.
3. Add a small margin for PAYG instalments and adjustments.
4. Don’t touch it for anything else.

When the BAS arrives, the money is already there. It turns a quarterly shock into a weekly routine — and it makes your operating balance an honest picture of what the business can actually spend.

How does BAS fit into a cash flow forecast?

Put the payment in the week it will actually leave the account, and put the weekly set-aside transfers in too. A 13-week cash flow forecast spans exactly one quarter, so every forecast will contain at least one BAS. If you pay wages, add super as well: under Payday Super, from 1 July 2026 contributions must reach employees’ funds within 7 business days of payday, according to the ATO.

If the forecast shows a BAS landing in the same fortnight as a large supplier payment and before a big customer receipt, you’ll see the pinch weeks in advance — with time to do something about it.

Seeing a BAS pinch coming? Check your options in a 60-second enquiry — no credit check is involved.

What if a BAS lands at a bad time?

Sometimes, despite good habits, a BAS is due when cash is short: a big customer is late, a seasonal dip ran longer, or growth absorbed more working capital than expected. The options, in order:

1. Lodge on time regardless. Lodging and paying are separate. Not lodging adds problems without solving any.

2. Contact the ATO before the due date. The ATO encourages businesses that can’t pay on time to get in touch early. It notes that businesses owing $200,000 or less may be able to set up a payment plan online.

3. Understand the cost of a plan. General interest charge accrues on the unpaid balance, and since 1 July 2025 GIC and shortfall interest charge are no longer tax deductible.

4. Consider a short-term loan if the gap is temporary. If the shortfall is a timing issue with a clear recovery — a debtor paying next month, a seasonal peak starting — a short-term loan can pay the BAS in full and be repaid from that recovery. Compare the after-tax dollar cost with a payment plan; our page on tax bill: loan or ATO payment plan sets out how, and is business loan interest tax deductible? covers the tax side.

5. Don’t stack. If you already have short-term debt, adding another loan to pay the BAS may be the wrong move. See avoiding debt stacking.

A BAS-season checklist

When	Action
Every week	Transfer GST and PAYG withheld to the tax account
Every week	Update the 13-week forecast
End of quarter	Reconcile accounts; confirm tax account balance matches the expected BAS
Two weeks before due	Draft BAS reviewed; any shortfall identified
One week before due	If short, contact the ATO or arrange funding — don’t wait
Due date	Lodge and pay (or lodge and have an arrangement in place)

Common BAS cash mistakes

• Treating GST as revenue. It sits in the account, it looks like money, and it gets spent.
• Forgetting PAYG withholding when wages rise or new staff start.
• Assuming the online extension applies without checking.
• Leaving quarter 2 to chance. The October–December quarter often includes the busiest trading of the year, so the GST collected can be larger than usual — and it falls due at the end of February, when many businesses are coming out of a quieter January.
• Missing the super change. From 1 July 2026, super no longer waits for the quarter.

What if you lodge monthly?

Monthly lodgers face twelve due dates a year, on the 21st of each following month — for example, the October 2026 period is due on 21 November 2026, which is a Saturday, so the weekend rule moves it to the next business day. Monthly lodgment is more work, but it can make cash planning easier: each payment is smaller, and the gap between collecting GST and paying it is shorter, so there’s less temptation to spend it.

The weekly set-aside routine works exactly the same way. The only change is that the tax account is drawn down every month rather than every quarter, so the balance you’re protecting never builds up as far.

When the numbers don’t line up

If a BAS is due and the tax account falls short because of a timing gap rather than a deeper problem, tell us about it — the amount, the due date and when the money that fixes the gap will arrive. A lending specialist will set out whether a short-term loan makes sense and what it would cost in dollars, so you can weigh it against an ATO arrangement. There’s no credit check to enquire, and your details stay with us rather than being sent around to other lenders. Please be accurate about any existing ATO debt or plan on the form; it changes which options are available.