BAS Due Dates for 2025–26 (and How Not to Miss One)
Every quarterly BAS deadline for 2025–26, how the tax-agent extension works, and why a late lodgement now costs more than it used to.
Missing a BAS deadline is one of the easiest ways to attract interest and penalties — and since 1 July 2025, that interest costs more than it used to. Here are the quarterly due dates for 2025–26, plus how lodging through a registered agent buys you more time.
The quarterly due dates
If you report and pay GST quarterly, these are the standard due dates for the 2025–26 financial year:
- Quarter 1 (Jul–Sep 2025): due 28 October 2025
- Quarter 2 (Oct–Dec 2025): due 28 February 2026
- Quarter 3 (Jan–Mar 2026): due 28 April 2026
- Quarter 4 (Apr–Jun 2026): due 28 July 2026
The tax-agent extension
Lodging through a registered BAS or tax agent generally gives you roughly a four-week concession on the quarterly deadline, provided your previous statements were lodged electronically and your account is in good standing.
There's one important exception: the December quarter (Q2). Its deadline is 28 February for everyone — the agent concession is already built into that later date, so there's no additional extension on that quarter.
Monthly and annual reporting
If you lodge monthly, your BAS is due on the 21st of the following month, and no agent extension applies. If you're voluntarily registered for GST and eligible to report annually, your annual GST return is generally due on 31 October after the end of the financial year.
Why timing matters more now
Late lodgement can trigger the general interest charge as well as failure-to-lodge penalties. From 1 July 2025, that ATO interest is no longer tax-deductible — so a late BAS is more expensive in real terms than it was in prior years. Building a simple lodgement calendar, or having an agent manage it, is the cheapest insurance available.
Key takeaways
- Quarterly BAS is due 28 Oct, 28 Feb, 28 Apr and 28 Jul for 2025–26.
- A registered agent usually adds about four weeks — except the December quarter.
- Monthly lodgers have no extension; annual GST is generally due 31 October.
- ATO interest on late amounts is no longer deductible, raising the real cost.
This article is general information current as at September 2025 and is based on published ATO guidance. Due dates can shift for weekends, public holidays and individual circumstances — confirm your specific dates with us.
Never miss a BAS again
Entrust Accounting can prepare and lodge your BAS on time, every quarter, with the agent extension applied where you're eligible.