What Are the BAS Due Dates for 2026?
If you’re searching “BAS due dates 2026 Australia” or “when is BAS due 2026,” you’re probably planning lodgement schedules or updating your compliance calendar. The ATO sets standard deadlines based on whether clients lodge quarterly or monthly.
For quarterly BAS lodgements in 2026, the general due dates follow the standard pattern:
- Q2 (October–December 2025) due 28 February 2026
- Q3 (January–March 2026) due 28 April 2026
- Q4 (April–June 2026) due 28 July 2026
- Q1 (July–September 2026) due 28 October 2026
If you are lodging through a registered tax or BAS agent, extended lodgement dates may apply, particularly for quarterly clients, depending on the ATO agent lodgement program.
Monthly BAS is generally due on the 21st day of the following month, unless that date falls on a weekend or public holiday.
What Accountants Need to Watch
The deadline itself is only part of the picture. The real pressure comes from volume and timing. When multiple quarterly clients fall due on the same date, even small reconciliation issues or GST coding errors can create bottlenecks.
Public holidays, bank feed disruptions, and delayed client documents often compress the real working window. If transactions are imported late, if duplicate bank entries appear after CSV uploads, or if GST treatment has drifted during the quarter, the last week before the BAS due date becomes reactive instead of controlled.
That’s why many firms search BAS deadlines not just to know the date, but to manage workflow risk ahead of it.
The Takeaway
The BAS due dates for 2026 in Australia are predictable. The pressure around them is not. Track quarterly and monthly deadlines clearly, confirm whether agent extensions apply, and review files early in the reporting period rather than waiting until the final week.
Deadlines don’t create BAS errors. Compressed review time does. The earlier reconciliation and GST consistency are reviewed, the smoother lodgement becomes when those 2026 due dates arrive.
