How to Pre-Check Your Business Activity Statement (BAS)
If your Australian enterprise holds an active ABN and is registered for Goods and Services Tax (GST), you must lodge periodic statements with the Australian Taxation Office (ATO). On each statement, you report the GST you collected on sales (Label 1A) and claim back the GST input tax credits you paid on business purchases (Label 1B).
Scope & Calculation Assumptions
To keep this pre-check utility streamlined for Australian sole traders and small businesses, the mathematical model assumes standard commercial operations:
- No Overseas Export Sales (G2 = $0): Assumes all taxable revenue is derived from domestic Australian supplies.
- No Input-Taxed Supplies (G4 = $0): Assumes your revenue does not include residential rent, financial supplies, or bank interest.
- No Non-Creditable Purchases (G13–G15 = $0): Assumes all logged expense receipts relate directly to taxable business operations without private use adjustments.
- No Decreasing Adjustments (G18 = $0): Assumes no bad debt write-offs or sales return adjustments during the reporting period.
The Official ATO Calculation Worksheet Method (NAT 3185)
Rather than relying on simplified gross estimates, our utility strictly adheres to the ATO GST Calculation Worksheet (NAT 3185):
- GST-Inclusive Sales Method: Subtracts GST-free supplies (G3) from gross sales (G1) to establish taxable turnover (G6), then applies the mathematical $1/11\text{th}$ formula ($G6 \div 11$) to extract Label 1A.
- GST-Exclusive Sales Method: If your accounting software records net income without tax, Label 1A is calculated as 10% of taxable turnover ($G6 \times 0.10$).
- Purchases & Input Credits (Label 1B): Business capital assets (G10) and operating expenses (G11) are logged as gross GST-inclusive receipts ($G17 = G10 + G11$), extracting input credits via $G17 \div 11$.
How to Read Your Calculation Result
arrow_upward Net Payable Position (1A > 1B)
When GST collected on sales exceeds GST credits on purchases, the positive difference is the net tax amount you must remit to the ATO by the quarterly due date.
arrow_downward Net Refund Position (1B > 1A)
When business setup assets or heavy operating expenses exceed GST collected, the ATO issues a refund directly into your nominated Australian bank account.
Quarterly BAS Due Dates Calendar
| Quarter | Period Covered | Standard Due Date |
|---|---|---|
| Q1 | 1 July – 30 September | 28 October |
| Q2 | 1 October – 31 December | 28 February |
| Q3 | 1 January – 31 March | 28 April |
| Q4 | 1 April – 30 June | 28 July |
Note: Lodging through a registered Tax or BAS Agent typically provides an automatic 4-week extension on quarterly lodgement deadlines. Refer to official ATO Activity Statement due dates.
What to Do Next
- Copy Your Figures: Use the "Copy BAS Summary" button above to preserve your Label 1A, Label 1B, and Net estimates for internal bookkeeping reference.
- Verify Tax Invoices: Ensure all claimed purchase expenses over $82.50 AUD are supported by a valid tax invoice listing the supplier's ABN.
- Submit Official Lodgement: Log into myGov or your business accounting portal (Xero, MYOB, QuickBooks) to formally submit your figures to the ATO.