John Jevi dela CruzBAS Due Dates: 7 Risky Errors to Avoid Now
BAS due dates can creep up fast. However, the real problem is usually not the BAS itself. Instead, it is the rushed process behind it. If you know the key BAS due dates and build a simple routine, you can reduce stress and avoid late lodgment.
This guide covers the main BAS due dates for 2026. It also explains the monthly GST shift and the errors that create avoidable cleanups.
BAS due dates: start with the date on your BAS
First, check the due date printed on your BAS. That is your main due date. Also, if the date falls on a weekend or public holiday, the next business day usually applies.
So, use reminders and calendars. However, always treat the date on the BAS as the final one to follow.
For official guidance, see:
https://www.ato.gov.au/businesses-and-organisations/preparing-lodging-and-paying/business-activity-statements-bas/due-dates-for-lodging-and-paying-your-bas
BAS due dates for monthly lodgers
If you lodge monthly, your BAS is usually due on the 21st day of the following month.
For example:
- January 2026 BAS: 21 February 2026
- February 2026 BAS: 21 March 2026
- March 2026 BAS: 21 April 2026
Because of that, monthly reporting needs a faster close. In other words, there is less room to catch up later.
BAS due dates for quarterly lodgers
If you lodge quarterly, the usual BAS due dates are:
- Quarter 1 (July to September 2025): 28 October 2025
- Quarter 2 (October to December 2025): 28 February 2026
- Quarter 3 (January to March 2026): 28 April 2026
- Quarter 4 (April to June 2026): 28 July 2026
This is where many people slip. The December quarter is not due in January. Instead, it is due on 28 February.
BAS due dates and extra time
If you lodge online, you may be eligible for an extra 2 weeks to lodge and pay your quarterly BAS. However, that extra time does not apply to quarter 2, because that quarter already includes a one-month extension.
Also, if you lodge through a registered BAS or tax agent, you may have different dates under the ATO lodgment program. So, confirm those dates early rather than assuming they will apply automatically.
You can check the official rules here:
https://www.ato.gov.au/businesses-and-organisations/preparing-lodging-and-paying/business-activity-statements-bas/due-dates-for-lodging-and-paying-your-bas
BAS due dates and the monthly GST shift
BAS due dates became more important after the ATO moved around 3,500 non-compliant small businesses from quarterly to monthly GST reporting from 1 April 2025.
That shift targeted businesses with a history of late lodgment, late payment, non-payment, or incorrect GST reporting. As a result, more businesses now need a tighter monthly routine.
Even if you still lodge quarterly, the lesson is clear. Clean books and on-time BAS reduce the chance of tougher compliance action later.
You can read the official update here:
https://www.ato.gov.au/media-centre/ato-shifts-non-compliant-businesses-to-monthly-gst
BAS due dates: 7 risky errors to avoid now
1) Forgetting the actual BAS date
Many people rely on memory. Instead, check the date printed on the BAS and put it in your calendar.
2) Waiting until BAS week to reconcile
This is one of the biggest causes of stress. Reconcile bank and credit card accounts earlier so BAS week becomes a review, not a rebuild.
3) Treating GST coding as a last-minute task
Small GST errors turn into bigger problems later. So, review GST treatment during the month or quarter, not only at the end.
4) Missing smaller income channels
Bank transfers, online payment links, side work, and one-off jobs still count. Therefore, make sure all income channels are captured.
5) Assuming quarter 2 is due in January
It is not. The December quarter is usually due on 28 February. Because of that, January is often a false comfort month.
6) Waiting too long to set cash aside
BAS is not only a form. It is also a cash flow event. So, set aside GST during the month or quarter rather than scrambling at the deadline.
7) Lodging on the last possible day
Last-day lodgment leaves no room for errors, missing receipts, or payment issues. Instead, finish early and give yourself a buffer.
BAS due dates: a simple routine that works
Use this short routine every month:
- reconcile bank and credit card accounts
- review GST exceptions
- check that all income is recorded
- file receipts and short notes together
- review cash set aside for BAS
- set a reminder before the due date
This routine is simple. However, it works because it spreads the work across the month instead of dumping it into one stressful week.
How HarvestWise Accounting can help
If BAS due dates keep creeping up on you, HarvestWise can help you build a cleaner routine. First, we can review your GST setup. Then, we can help you tighten reconciliations and create a simple month-end routine.
BAS lodgement service:
https://harvestwiseaccounting.com.au/services/bas-lodgement/
Bookkeeping support:
https://harvestwiseaccounting.com.au/services/bookkeeping/
Tax return services:
https://harvestwiseaccounting.com.au/services/tax-returns/
Contact us:
https://harvestwiseaccounting.com.au/contact-us/
More guides:
https://harvestwiseaccounting.com.au/blog/
Disclaimer
General information only. Tax outcomes depend on your circumstances. Speak to a registered tax professional for advice.
The monthly BAS timing, quarterly BAS dates, online-lodgment extra-time rule, and the monthly GST shift from 1 April 2025 align with current ATO guidance.