If the letters "BAS" make your stomach drop a little, you're not alone. The good news: for a sole trader tradie it's a lot simpler than it looks. Strip away the jargon and it's basically a quarterly form telling the ATO how much GST you collected and how much you paid. That's the heart of it.
What is a BAS, really?
BAS stands for Business Activity Statement. It's the form you lodge with the ATO — usually every quarter — to report and pay (or get refunded) a few things at once. For most sole trader tradies the big one is GST. Depending on how you're set up it can also cover PAYG instalments (a prepayment toward your income tax) and PAYG withholding (if you pay wages), but GST is the part that trips most people up, so that's where we'll focus.
Think of it like this: every quarter you tally up the GST you charged your customers, subtract the GST you paid on business expenses, and the difference is what you send the ATO. If you paid more GST than you collected, you can get money back.
GST basics in two minutes
GST (Goods and Services Tax) is a flat 10% added to most things you sell. If you're registered for GST, every invoice you send should add 10% on top of your price, and that extra bit isn't yours to keep — you're collecting it on behalf of the ATO.
The flip side: when you buy fuel, materials, tools, or pay for business services, you're usually paying GST too. Because you're registered, you can claim that back as a GST credit. So you only ever hand over the net amount.
Do you even need to register?
You must register for GST once your turnover reaches the $75,000 threshold in a year (or you expect it to). Below that, registering is optional — some tradies do it voluntarily so they can claim GST credits on gear, others hold off to keep things simple. Worth a quick chat with your accountant before deciding.
The two numbers that matter: GST collected (the 10% you added to customer invoices — this is label 1A on your BAS) and GST paid (the GST on your business purchases — label 1B). Your BAS payment is roughly 1A minus 1B.
What you need to track
BAS gets painful when you're reconstructing a whole quarter from a glovebox full of crumpled receipts. It gets easy when the numbers are already sitting there. Here's what to keep on top of:
- Every invoice you issue — the amount, the GST on it, and whether it's been paid. This builds your "GST collected" total.
- Every business expense — fuel, materials, tools, subbies, software, phone. Keep the tax invoice or receipt, and note the GST.
- Vehicle and fuel records — fuel and running costs carry GST credits, and your mileage feeds into your income tax claim too.
- Anything GST-free or out of scope — not everything has GST on it, so keep those separate rather than assuming 10% on the lot.
The ATO generally wants you to keep these records for five years. So whatever system you use, make sure it actually holds onto the detail — not just a total.
Doing it as-you-go vs the shoebox
There are two ways to run BAS. The shoebox way: ignore it for three months, then panic, tip out a pile of receipts, and try to remember which job that bunnings run was for. The as-you-go way: every quote, invoice and expense is captured the moment it happens, so at quarter's end you just check the totals and lodge.
As-you-go wins every time, for three reasons:
- You don't lose claims. A faded receipt that fell behind the seat is GST you'll never get back. Capture it on the spot and it's banked.
- No quarter-end scramble. The numbers are already done. BAS becomes a five-minute check, not a lost weekend.
- You actually know where you stand. If you can see your GST position any day of the quarter, there are no nasty surprises when the bill lands.
Common mistakes that catch tradies out
- Spending the GST. The 10% on your invoices isn't profit — it's the ATO's money sitting in your account. Treat it as set aside, or you'll feel the pinch at BAS time. Some tradies park it in a separate account.
- Forgetting to claim GST credits. Every business purchase with GST on it is a credit. Miss the receipts and you overpay.
- Claiming GST on things that don't have it. Some expenses are GST-free. Claiming 10% where there wasn't any is an error the ATO can pick up.
- Counting voided or credited invoices. If you void an invoice or issue a credit note, that GST shouldn't still be in your collected total. Make sure your records subtract it.
- Mixing personal and business. Keep them separate. A business account and clean records save hours and headaches.
- Lodging late. Even a nil BAS needs to go in. Missing the due date can mean penalties.
How FieldForge makes BAS painless
FieldForge tracks the money coming in (your quotes and invoices) and going out (expenses, fuel, materials) as it happens — with the GST captured on each one. At any point you can open a BAS-ready summary: GST collected (1A), GST paid (1B), and your net position, with a PDF you can hand straight to your accountant.
Voided invoices and credit notes are subtracted so your headline GST matches reality. Fuel and vehicle records are kept for the ATO's five-year window automatically. It's the as-you-go approach, built in — so quarter's end is a quick check, not a scramble. See all the features →
The bottom line
BAS isn't the monster it's made out to be. Register if you need to, charge GST on your invoices, keep every receipt, set the GST aside, and lodge on time. Capture it all as you go and you'll never dread the form again. Do the boring bits well and BAS becomes a five-minute job.