BAS Due Dates 2026-27: Every Deadline Australian SMEs Need to Know

Your BAS due dates aren't the same for every business — they depend on how often you lodge, how you lodge, and whether you use a registered agent. Rather than a list of dates that will be out of step with your situation, here's how the deadlines actually work so you can pin down yours with confidence and stop being surprised by them.

First, know your reporting cycle

Your Business Activity Statement reports GST and, depending on your registrations, PAYG withholding, PAYG instalments and a few other obligations. The frequency the ATO assigns you drives everything:

• Quarterly is the most common cycle for small businesses. You lodge four times a year for the periods ending in the last month of each quarter.
• Monthly lodgers report each month, typically because turnover is above the threshold at which the ATO requires it, or by choice.
• Annual GST reporting is available to some smaller businesses that have elected it and meet the ATO's conditions.

You can confirm your assigned cycle in the ATO's online services or on the BAS itself. If your circumstances have changed, your cycle can change too, so don't assume this year mirrors last.

How the quarterly deadlines are set

For quarterly lodgers, each BAS is due a set period after the end of the quarter. The pattern is consistent: the standard due date falls a fixed number of weeks after the quarter closes, with the exception of the quarter that ends around the Christmas period, which the ATO gives extra time to account for the holidays. Because the exact dates shift when a due date lands on a weekend or public holiday (it rolls to the next business day), the reliable move is to read the current due date off your own BAS or the ATO's BAS due dates page rather than memorising a number.

Lodging through a registered agent usually buys you time

If a registered BAS or tax agent lodges on your behalf, you're generally entitled to a later due date than if you lodge yourself — the ATO operates a lodgment program that extends deadlines for agent-lodged statements. This is one of the quieter benefits of using an agent, and it applies even if the agent is simply lodging a return you've prepared. To get the concession you typically need to be on the agent's client list before the relevant date, so it's worth sorting the relationship out well ahead of a deadline, not the week it's due.

Paying is a separate obligation from lodging

A trap worth flagging: the date you must lodge and the date you must pay can differ, and interest accrues on amounts paid late even where lodgment was on time. If cash flow is tight, lodge on time regardless — lodging late attracts its own consequences — and talk to the ATO or your agent about a payment arrangement rather than simply not lodging. The ATO is markedly more accommodating with businesses that stay in contact and keep lodging.

Build a system so dates never sneak up

The businesses that never miss a BAS treat it as a rhythm, not an event. A few habits that work:

• Reconcile your accounts as you go, so preparing the BAS is a review rather than a scramble.
• Set your own internal deadline a week or two before the real one, and diarise it as a recurring task rather than relying on memory.
• Set aside GST and PAYG amounts as they're collected — ideally in a separate account — so the money is there when the payment falls due.
• Keep your agent relationship current if you use one, so you retain the extended lodgment dates.

Getting this right is core to your finance function and closely tied to keeping the whole back office connected, so the numbers you report are already reconciled rather than assembled at the last minute. Because due dates, thresholds and concessions do change, always confirm your specific dates against the ATO's current BAS due dates page or with your registered agent. This is general information, not tax advice for your circumstances.