BAS due dates and ATO deadlines: Your 2026–27 lodgement calendar
Stay ahead of BAS due dates and ATO deadlines to avoid costly penalties and needless stress.
Written by Naomi Lai— Small business & finance writer. Read Naomi's full bio
Published Thursday 9 July 2026
Table of contents
Key takeaways
- Monthly BAS is due on the 21st of the following month, and quarterly BAS is due on the 28th of the month after the quarter ends, except the October to December quarter, which is due 28 February.
- Your income tax return and any PAYG instalments have their own due dates, so put them in your calendar alongside your BAS.
- Lodging your quarterly BAS online usually adds about two weeks, and a registered agent can lodge on later concession dates.
- Missing a deadline can bring a failure to lodge penalty and interest on unpaid amounts, so a few simple routines pay off.
Your BAS due dates and other ATO deadlines
Knowing your business activity statement (BAS) due dates is the simplest way to stay on the right side of the ATO. Your GST reporting cycle sets how often you lodge, and the Australian Taxation Office (ATO) publishes the due date for each period.
Monthly BAS is due on the 21st of the month following the taxable period. Quarterly BAS is due on the 28th of the month after the quarter ends, with one exception: the October to December quarter is due on 28 February.
According to the ATO, the standard quarterly BAS due dates for the 2026–27 financial year are:
- Q1 (Jul–Sep): 28 October 2026
- Q2 (Oct–Dec): 28 February 2027 (this falls on a Sunday so the effective date is Monday, 1 March 2027)
- Q3 (Jan–Mar): 28 April 2027
- Q4 (Apr–Jun): 28 July 2027
If you report and pay GST annually, your annual GST return is due when your income tax return is due, which is 31 October when you must lodge a return. If you don't need to lodge an income tax return, it's due on 28 February.
Other ATO dates to put in your calendar
Your BAS isn't the only date that matters when you're self-employed. A couple of other ATO deadlines can sneak up on you, so it helps to know when they fall.
Your income tax return
If you lodge your own income tax return, it's due on 31 October. If you lodge through a registered tax agent instead, they'll usually have a later date, as long as you're on their books before the October deadline.
PAYG instalments
If the ATO has entered you into the pay as you go (PAYG) instalments system, you prepay tax on your business income across the year. These instalments are generally due 28 days after the end of each quarter and are reported on your activity statement, so they often line up with your BAS.
How lodging online or with an agent gives you more time
You can often earn a little breathing room on your quarterly BAS just by changing how you lodge. Two options give you more time before the due date.
Lodging your quarterly BAS online usually gives you an extra two weeks beyond the standard date. The October to December quarter is the exception, because its 28 February due date already includes a one-month allowance.
A registered BAS or tax agent can also lodge for you on later concession dates. If deadlines tend to creep up on you, getting comfortable with the ATO due dates for lodging and paying and choosing the right lodgement method can make each cycle less of a scramble.
What missing a BAS or ATO deadline actually costs
Missing a due date is one of the more avoidable ATO mistakes, and it can get expensive. Here's what a late lodgement or payment can cost you.
Failure to lodge on time penalties
Failure to lodge on time (FTL) penalties are fines from the ATO when you don't lodge your BAS or income tax return by the due date. The amount varies with your circumstances, such as the size and type of your business and how far past the due date you are.
Interest on amounts you pay late
Lodging on time is only half the job; paying on time matters too. Any amount that stays unpaid after its due date can attract the general interest charge, which builds up daily until you clear the balance.
Asking for a penalty to be remitted
A missed deadline isn't always the end of the story. If you have a good reason, you can ask the ATO to remit all or part of a penalty or interest charge, and it may take your situation into account.
How to stay on top of every deadline
Staying on top of your BAS due dates and other ATO deadlines comes down to a few simple habits rather than a last-minute rush. Build these routines into your year and each due date becomes a non-event.
- Set a calendar reminder for every due date. Add each BAS, income tax and instalment date, with an alert a week or two out.
- Set aside your GST and tax money as you go. Move it to a separate account so it's ready when the date arrives.
- Reconcile your accounts regularly. Keeping your figures current means your numbers are ready well before the deadline.
- Lodge with SBR-enabled software. Standard business reporting (SBR) accounting software lets you lodge your BAS on time, straight from your records.
Getting familiar with the basics of lodging your business activity statement also makes each cycle quicker, so the date arrives with the work already done.
Simplify BAS deadlines with Xero
Chasing due dates takes attention away from what you'd rather be doing, which is running your business. Xero is standard business reporting (SBR) enabled accounting software that keeps your figures reconciled and lets you lodge your BAS on time, so deadlines stop being a scramble.
Keen to keep every BAS and ATO deadline under control?
FAQs on BAS due dates and ATO deadlines
Still have a few questions about due dates? Here are quick answers to common ones.
When is my BAS due?
If you lodge monthly, your BAS is due on the 21st of the following month. If you lodge quarterly, it's due on the 28th of the month after the quarter ends, except the October to December quarter, which is due on 28 February.
What happens if I lodge my BAS late?
You can receive a failure to lodge on time penalty, and any amount left unpaid after the due date can attract the general interest charge. If you have a good reason, you can ask the ATO to remit the penalty or interest.
Do I get more time if I use a registered agent?
Yes. A registered BAS or tax agent can lodge on later concession dates, and lodging your quarterly BAS online usually adds about two weeks on top of the standard due date.
When is my income tax return due?
If you lodge it yourself, your income tax return is due on 31 October. If you lodge through a registered tax agent, you'll usually get a later date, provided you're on their books before that October deadline.
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