BAS for beginners: a tradie’s guide to Business Activity Statements

Starting out as a sole-trader tradie comes with a lot of new paperwork, and one of the biggest acronyms you'll hear thrown around on the job site is the "BAS". If you're staring at an Australian Taxation Office (ATO) notification and wondering what on earth you need to do next, you aren't alone. Transitioning from being an employee to running your own show means taking charge of your own taxes, which can feel incredibly overwhelming at first.

This guide to BAS for beginners will break down exactly what a Business Activity Statement is, entirely without the accounting jargon. We'll cover what it is, when it's due, what goes on it, and how you can stay on top of your numbers so you can spend less time stressing over paperwork and more time doing what you do best.

What a BAS is

When your tradie business grows and you hit a certain annual income milestone, you are legally required to sign up for GST registration. Once you do, the ATO needs you to regularly report how much Goods and Services Tax (GST) you've collected from your customers on their behalf, and how much GST you've paid out of your own pocket on business expenses.

If you're GST-registered you report and pay GST quarterly on a Business Activity Statement (BAS). Think of your BAS as a regular health check and summary of your business tax obligations over a specific period. Instead of waiting until the end of the financial year to settle up—which could leave you with one massive, unmanageable tax bill—the BAS system helps you pay it in smaller, manageable chunks. While there are a few different reporting cycles available depending on the size of a company, most small businesses lodge quarterly. This strikes a good balance between keeping your cash flow steady and minimizing the amount of administrative work you have to do.

When it's due

Missing an ATO deadline can result in unnecessary late fees and penalty interest, so it pays to mark these dates clearly in your diary or phone calendar. The specific cut-off dates depend on how you choose to lodge your statement.

For FY2026-27 the quarterly BAS due dates are: Q1 (Jul-Sep 2026) due 28 Oct 2026 (paper) / 11 Nov 2026 (online) / 25 Nov 2026 (through a registered agent); Q2 (Oct-Dec 2026) due 1 Mar 2027 (the standard 28 Feb falls on a Sunday, so it moves to Mon 1 Mar); Q3 (Jan-Mar 2027) due 28 Apr 2027 / 12 May 2027 (agent); Q4 (Apr-Jun 2027) due 28 Jul 2027 / 11 Aug 2027 (agent).

As you can see, choosing to lodge online through the ATO portal or using a registered tax or BAS agent usually buys you a bit of extra breathing room.

What goes on it — G1, 1A, and 1B

When you look at a blank BAS for the first time, you'll see a bunch of boxes with alphanumeric codes next to them. It looks intimidating, but as a typical sole-trader tradie, you generally only need to worry about three main fields to get your GST sorted.

Here are the key BAS labels: G1 = total sales GST-inclusive, 1A = GST on sales, 1B = GST credits (purchases).

To break that down into plain English:

G1 is the grand total of all the money your business brought in over the quarter. Crucially, it includes the GST you charged your clients.

1A is the specific portion of your total sales that is just the GST you collected. This is the money that isn't yours; you owe it to the ATO. To calculate this quickly, remember this handy rule: The GST in a GST-inclusive amount is that amount divided by 11. For example, if you charged a client $1,100 total, you divide that by 11 to find out that $100 is the GST portion.

1B is the GST you have paid on valid business expenses over the quarter—like building materials, fuel for your work ute, or new power tools. You get to claim this money back.

Your final GST bill for the quarter is simply a matter of simple subtraction: 1A minus 1B. If you collected more GST than you paid out, you owe the ATO the difference. If you paid more GST on materials than you collected from clients, you will receive a refund. Making sure you are sending out compliant, correctly formatted invoices guarantees you have accurate numbers to drop into these boxes.

How VoiceTradie keeps it ready

Tackling a BAS for beginners can be frustrating if you're trying to do it from a crumpled pile of faded hardware store receipts living in your glovebox. The trick to stress-free lodging is having a reliable system that tracks your money as it moves. You didn't become a tradie to sit behind a desk doing endless data entry, which is exactly where VoiceTradie comes in.

Our app is built from the ground up for Australian sole-traders who want to manage their admin using nothing but their voice. Instead of typing out fiddly line items on a tiny phone screen at the end of a long day on the tools, you just speak naturally to the app. VoiceTradie automatically generates your invoices, calculates the exact GST for you, and keeps a pristine, running total of your income. When the end of the quarter arrives, your G1 and 1A figures are already perfectly tallied up and waiting for you.

Ready to ditch the paperwork panic and make your next quarterly lodgment a total breeze? Start sorting your invoicing the smart way today. Check out our pricing and discover how easy it is to run your tradie business right from the driver's seat.