Work through this top to bottom every quarter and nothing gets missed. It takes about an hour the first time, less each quarter after that.
One-time setup, do this first
- ☐ Confirm your reporting basis: cash or accruals. Cash is the default choice for most sole traders and matches your bank statement.
- ☐ Keep business money in a separate account. Mixing personal and business transactions is the single biggest time sink in BAS prep.
- ☐ Not registered for GST yet? You only lodge a BAS once your turnover passes $75,000. Until then, skip this page entirely.
Gather, before you touch any numbers
- ☐ All sales invoices for the quarter, or your income records if you invoice as you go.
- ☐ Expense receipts and invoices, especially anything paid by cash or personal card.
- ☐ Business bank and credit card statements for the full quarter.
- ☐ Your previous BAS, for comparison.
- ☐ Your PAYG instalment notice, if the ATO has put you on instalments.
Work the numbers
- ☐ G1: total sales including GST, and including GST-free income.
- ☐ 1A: GST collected. Divide each GST-inclusive taxable sale by 11.
- ☐ 1B: GST paid on business purchases. Divide GST-inclusive purchases by 11, but only the business-use share of mixed purchases.
- ☐ W1 and W2: almost always nil for a sole trader with no employees. Leave blank, don't put zero transactions there.
- ☐ T7: enter your PAYG instalment amount if the ATO has you on the instalments system.
Sanity checks before you lodge
- ☐ Pick one invoice and redo its GST by hand. If the tool or spreadsheet disagrees with you, stop and find out why.
- ☐ Compare 1A with last quarter. A similar figure is normal. A sudden jump or drop needs an explanation before you lodge, not after.
- ☐ GST-free income appears in G1 but must not appear in 1A.
- ☐ No GST claimed on bank fees, interest, wages, or super. None of them carry GST.
- ☐ Check quarter boundaries. On the cash basis, a payment counts in the quarter the money moved, not the invoice date.
Lodge and pay
- ☐ Check the deadline on our BAS due dates page.
- ☐ Lodge through ATO online services via myGov, or through your registered agent.
- ☐ Pay by the due date. If you can't pay in full, lodge anyway and contact the ATO about a payment plan. Lodging late costs more than owing.
- ☐ Save the lodgement confirmation.
After lodging
- ☐ File everything. The ATO requires records be kept for five years.
- ☐ Note anything you'll do differently next quarter, like chasing receipts weekly instead of quarterly.
- ☐ Set a phone reminder for the next due date.
Where the kit fits
Steps two to four are exactly what the ClearQuarter kit automates: enter income and expenses once, and it splits GST, tags each transaction to the right quarter, and produces G1, 1A, 1B with a built-in sanity check. The checklist above still applies; the kit just does the arithmetic and the sorting for you.