BAS for Sole Traders: The No-Jargon Guide for Tradies

Updated 8 July 2026

A Business Activity Statement (BAS) is the form GST-registered businesses send the ATO — usually every quarter — reporting the GST collected on sales and the GST paid on expenses. The difference is what you pay (or get refunded). If you’re a sole trader registered for GST, BAS is not optional; if you’re not registered, you don’t lodge one at all.

Who actually has to lodge a BAS

You must register for GST — and therefore lodge BAS — once your GST turnover reaches $75,000 a year. Under that, registration is optional. Two practical notes for tradies:

• Turnover means your gross business income, not your profit after tools and fuel.
• You must register within 21 days of becoming aware you’ll cross the threshold — not at the end of the year. A busy tradie doing $1,500+ a week is already there.

If you’re not GST-registered: no BAS, no GST on your invoices, and you can’t claim GST credits on what you buy. Your invoices are regular invoices, not "tax invoices" — more on that in how to invoice as a tradie.

The quarterly due dates

Most sole traders lodge quarterly. The standard due dates are:

Lodging online through ATO Online services generally gets you up to two extra weeks on most quarters, and a registered tax or BAS agent gets longer again. Q2’s date is already pushed out because of Christmas.

What's actually on the form

For a typical sole trader tradie, three numbers do most of the work:

• G1 — total sales for the quarter.
• 1A — GST on sales: the 10% GST you collected on your invoices.
• 1B — GST on purchases: the GST inside what you bought for the business — materials, fuel, tools, this app.

You pay the ATO 1A minus 1B. If you bought a lot that quarter (say a new trailer), 1B can exceed 1A and the ATO refunds you. If you pay income tax by instalments (PAYG), that amount also appears on the BAS.

Watch-outs that catch tradies

• Not everything has GST in it. Bank fees, most insurance stamp duty components, council rates and wages don’t carry GST — claiming 10% of everything is the classic error.
• No tax invoice, no GST credit. For purchases over $82.50 (GST inclusive) you need a tax invoice to claim the credit. Photograph receipts when you get them; thermal paper dies in a ute.
• The GST you collect was never yours. The quarter goes fine until the BAS bill lands. Put roughly 1/11 of each payment aside as it comes in and the due date is boring instead of brutal.
• Private use isn’t claimable. If the ute or the phone is part personal, only the business share of the GST is claimable.

How to make BAS a ten-minute job

The BAS itself is easy when the quarter behind it is clean. That means every invoice issued with GST calculated, every expense logged with its receipt and GST amount, all in one place. TradieMate does exactly this — GST is tracked at 10% automatically on income and expenses, and at quarter's end it generates an ATO-ready BAS report as a PDF with the G1/1A/1B numbers ready to copy into ATO Online services (or hand to your agent). See how it works in the feature tour, or read how it compares to other sole trader apps.

This guide is general information, not tax, legal or financial advice. Rules and rates change — check current details with the ATO or a registered tax agent before acting on it.