The quarterly BAS checklist for sole traders
15 things to tick off each quarter, in the order you do them: what to gather, how to categorise, which label gets which figure, how to lodge through ATO Online, and what to do after. Print it and stick it above the desk, or have it emailed so it is there when the due date comes round.
Updated 17 September 2026. General information for Australian sole traders, not tax advice.
Quarterly BAS due dates
| Q1 | July to September | 28 October |
| Q2 | October to December | 28 February |
| Q3 | January to March | 28 April |
| Q4 | April to June | 28 July |
If a due date falls on a weekend or public holiday you have until the next business day. Lodging through a registered BAS or tax agent usually gives you longer. Monthly lodgers are due on the 21st of the following month.
Before you start
- 1.Export the quarter’s bank statement
Download a CSV or PDF from your bank for every account you run the business through, covering the first to the last day of the quarter.
- 2.Gather your receipts
Photos, emailed PDFs and the paper ones in the glovebox. The ATO expects a record for each purchase you claim GST on.
- 3.List the invoices you issued
Check every invoice for the quarter has been recorded, including any paid in cash or still unpaid, so your sales figure is complete.
Categorise
- 4.Review the uncertain transactions
Anything that could be business or personal, a transfer between your own accounts, or a one-off you do not recognise. Decide and note it.
- 5.Check GST on purchases
Not every business expense includes GST. Bank fees, most insurance stamp duty, overseas subscriptions and suppliers not registered for GST are common ones to check before you claim.
- 6.Split private use
Phone, internet, vehicle and home office costs are usually part business, part private. Claim only the business share and keep a note of how you worked it out.
Labels
- 7.G1 total sales and 1A GST on sales
G1 is all sales for the quarter including GST. 1A is the GST you collected on them, usually one eleventh of your GST-inclusive taxable sales.
- 8.G10 capital purchases and G11 non-capital purchases
G10 is larger assets such as equipment or a vehicle. G11 is day-to-day running costs. Both are GST-inclusive figures.
- 9.1B GST on purchases
The GST you paid on business purchases and can claim back. Only include purchases that had GST in them and that you hold a record for.
- 10.PAYG instalment, if it appears
If the ATO has put you in the PAYG instalment system the label is on your statement with a pre-filled amount. Check it against how the quarter went and vary it if your income has changed a lot.
Lodge
- 11.Log in to ATO Online and open the statement
Go to my.gov.au, sign in, open the Australian Taxation Office, then Business, Lodgments, Activity statements. Pick the quarter.
- 12.Enter each label in whole dollars and lodge
Copy the figures across, no cents. The form works out what you owe or are owed. Review the declaration and lodge.
- 13.Pay by the due date
Use the payment reference number on the statement. If you are due a refund the ATO pays it to the bank account they have on file for you.
After
- 14.File the PDF with your records
Save the lodged statement and the receipts behind it together. Records need to be kept for five years.
- 15.Set aside for next quarter
Move the GST from each payment you receive, and a share for income tax, into a separate account as you go, so the next BAS is already funded.
General information for Australian sole traders, not tax advice. Your activity statement may carry other labels depending on your registrations, for example PAYG withholding if you employ anyone. Check your own situation with the ATO or a registered BAS or tax agent.
Email me the quarterly BAS checklist
The checklist now, then a few short notes on getting your BAS done. No spam, unsubscribe any time.
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Upload the quarter's bank statement and the AI categorises every transaction, works out the GST and puts each label on a copy-ready card for ATO Online. The categorising and the labels take minutes instead of a Sunday.
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