Australia BAS Preparation Checklist for Founders
A tidy BAS starts with tidy books: every sale and purchase coded with the right GST treatment, bank accounts reconciled, payroll and PAYG withholding reconciled, and a second review before your registered BAS agent lodges. Quarterly BAS is generally due 28 October, 28 February, 28 April and 28 July. OmniScope360 does not lodge BAS; it helps you prepare the numbers and the cash to pay.
Before the quarter ends
- Make sure invoices and bills are entered and coded
- Check GST codes on recurring items
- Keep receipts and tax invoices for purchases
Reconcile
- Reconcile every bank and credit card account
- Review uncategorised transactions
- Reconcile the GST clearing account to the BAS workings
- Reconcile PAYG withholding and payroll liabilities to payroll reports
Check the main BAS items
- GST on sales and GST credits on purchases
- PAYG withholding amounts
- Any instalment amounts you are registered for
- Superannuation is paid separately and has its own due dates; check the ATO
Cash to pay
Put the BAS payment into your 13-week cash forecast so the due date never surprises you. Set aside GST and PAYG as the quarter goes.
Lodge and keep records
- A registered BAS agent or tax practitioner lodges where you use one
- Keep the lodged BAS and the workings together
- Providing BAS services for a fee requires Tax Practitioners Board registration, which is why OmniScope360 does not lodge BAS
Source and review date
Source: Australian Taxation Office (ato.gov.au). Reviewed 19 October 2026. Your own due dates are in your ATO account.
Frequently asked questions
Quarterly BAS is generally due 28 October, 28 February, 28 April and 28 July. Some businesses report monthly. Check your ATO account.
Do you lodge BAS?No. Lodging BAS for a fee requires registration with the Tax Practitioners Board. OmniScope360 prepares forecasts, reporting and controls and works with your registered agent.
What is the GST registration threshold?A$75,000 of GST turnover for most businesses (A$150,000 for non-profits). Taxi and ride-sourcing providers must register regardless.
Want this set up for your startup?
Book a free discovery call. We review your numbers and agree what to fix first, with no cost and no obligation.
Written by Akram El-Karrar, CPA, from the work we do for startups every week.