If you’ve ever searched “BAS due date” at 11pm the night before you think it might be due, you’re not alone. Between quarterly cycles, monthly cycles, and the extra time you get for using a registered agent, it’s genuinely confusing — and getting it wrong costs real money. Here’s the full picture.
If you’re not sure what actually goes into a BAS in the first place, our plain-English guide to what a BAS statement actually is covers that.
Quarterly BAS due dates (lodging it yourself)
If you lodge your own BAS, the standard quarterly due dates are the same every year:
| Quarter | Period | Due date |
|---|---|---|
| Quarter 1 | July – September | 28 October |
| Quarter 2 | October – December | 28 February |
| Quarter 3 | January – March | 28 April |
| Quarter 4 | April – June | 28 July |
If a due date falls on a weekend or public holiday, it moves to the next business day.
The registered agent concession — extra time, legitimately
Here’s the part most business owners don’t know: if you lodge electronically through a registered BAS agent or tax agent, the ATO gives you extra time on most quarters. Under the current 2026–27 registered agent lodgment program:
| Quarter | Standard due date | Registered agent due date |
|---|---|---|
| Q4 2025–26 (Apr–Jun 2026) | 28 July 2026 | 25 August 2026 |
| Q1 2026–27 (Jul–Sep 2026) | 28 October 2026 | 25 November 2026 |
| Q2 2026–27 (Oct–Dec 2026) | 28 February 2027 | 28 February 2027 (no change) |
| Q3 2026–27 (Jan–Mar 2027) | 28 April 2027 | 26 May 2027 |
Worth flagging right now: if your business is on quarterly BAS and you’re with a registered agent, your April–June 2026 BAS isn’t due until 25 August 2026 — not 28 July. That’s an easy one to miss if you’re used to doing it yourself.
Monthly BAS due dates
If your business lodges monthly (usually because of turnover, or by choice for better cash flow visibility), BAS is due on the 21st of the following month — every month, no quarterly variation. If you’re also juggling Single Touch Payroll and Payday Super obligations on top of BAS, our guide to STP, Payday Super and IAS covers those.
What happens if you miss it
The ATO’s failure-to-lodge penalty is charged per 28-day period the BAS is overdue, up to a cap. As of 1 July 2026 the penalty unit rose to $364, which puts the maximum failure-to-lodge penalty for a small business at $1,820 — a real cost for something that’s entirely avoidable with the right reminders in place.
How Dedicated Bookkeeping keeps you ahead of every deadline
This is exactly the kind of thing that falls through the cracks when you’re running a business, not tracking ATO lodgment calendars. As a registered BAS agent, we lodge on the agent concession dates automatically — so you get the extra weeks without having to know they exist. Because your books are kept current in real time rather than reconstructed in a rush, there’s no scramble the week it’s due. And pricing is agreed with you up front, so there’s no surprise invoice attached to it either.
If deadlines have been a source of stress rather than something handled quietly in the background, that’s worth a conversation.
Frequently Asked Questions
When are BAS statements due?
For self-lodgers, quarterly BAS is due 28 October, 28 February, 28 April, and 28 July. If you lodge through a registered BAS agent, most quarters get extra time — for example, the April–June 2026 BAS isn’t due until 25 August 2026 for registered agent clients.
Does using a bookkeeper give me more time to lodge my BAS?
Yes — if they’re a registered BAS agent lodging electronically on your behalf, the ATO’s registered agent concession applies, generally adding two to four extra weeks on most quarters.
What happens if I lodge my BAS late?
The ATO charges a failure-to-lodge penalty per 28-day period overdue, up to a cap. As of 1 July 2026, the maximum penalty for a small business is $1,820.
How often do I need to lodge a BAS?
Most small businesses lodge quarterly. Businesses with turnover generally above $20 million lodge monthly, and some smaller businesses choose monthly lodgment for better cash flow visibility.