For a lot of tradies, "BAS is due" means a weekend buried in a shoebox of faded receipts. It really doesn't have to. Once you understand what the ATO actually wants and keep decent records through the quarter, BAS becomes a quick admin task instead of a dread.
What actually goes on a BAS
For most sole-trader tradies, the BAS is mainly about GST. The core figures are:
- GST collected — the 10% you charged customers on your sales.
- GST paid (credits) — the GST you paid on materials, tools, fuel and other business expenses.
- PAYG instalments — pre-payments towards your income tax, if the ATO has you in that system.
- PAYG withholding — tax you withheld from employees' wages, if you have staff.
When it is due
Most tradies lodge quarterly. The standard due dates are:
- Q1 (Jul–Sep) — due 28 October
- Q2 (Oct–Dec) — due 28 February
- Q3 (Jan–Mar) — due 28 April
- Q4 (Apr–Jun) — due 28 July
Lodge through a registered agent and you usually get extra time. Miss a deadline and you risk penalties and interest — so it pays to stay on top of it.
How to make BAS painless
The whole game is records through the quarter, not a scramble at the end:
- Keep every tax invoice you issue and every receipt you pay — digitally, not in the glovebox.
- Track GST on both sides as you go, so the totals are already there at BAS time.
- Set aside the GST you collect so the bill is never a nasty surprise.
- Make sure your invoices are correct in the first place — a compliant tax invoice is what makes the GST figure trustworthy.
Free GST Calculator
Quickly work out the GST on any sale or purchase — handy for sanity-checking your figures before you lodge, or when you are setting money aside each job.
Open the free toolFrequently asked questions
A Business Activity Statement is the form you lodge with the ATO to report and pay your GST, and often your PAYG instalments and PAYG withholding if you have staff. If you are registered for GST, you have to lodge a BAS — usually every quarter. It is basically how you tell the ATO how much GST you collected and how much you paid.
Most tradies lodge quarterly. The standard due dates are 28 October, 28 February, 28 April and 28 July for the four quarters. If you lodge through a registered BAS or tax agent you often get a bit longer. Monthly and annual cycles exist too, depending on your turnover and setup.
You pay the GST you collected on sales, minus the GST you paid on business purchases (your credits). So if you collected $6,000 of GST and paid $2,000 of GST on materials and expenses, you remit $4,000. Keeping accurate records of both sides is what makes this simple instead of stressful.
Not necessarily — many tradies lodge their own BAS online through the ATO. But a registered BAS or tax agent can save you time, catch credits you missed and give you longer to lodge. Either way, the key is good record-keeping through the quarter so BAS time is a five-minute job, not a weekend of receipts.
Make BAS time a non-event
Admin Substitute keeps every invoice and the GST on it in one place, so your quarterly totals are always ready — no shoebox, no weekend, no surprises. From $8/day.
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