Overview of Australian Activity Statement Obligations
Once an Australian enterprise crosses the $75,000 GST threshold (or registers voluntarily), it must regularly lodge a Business Activity Statement (BAS) with the Australian Taxation Office (ATO). Your BAS is used to report and pay GST collected, claim input tax credits, report Pay As You Go (PAYG) withholding from employee wages, and settle PAYG income tax instalments.
2026–2027 Quarterly BAS Lodgement Calendar
Most Australian small businesses report GST quarterly. Standard lodgement and payment deadlines occur on the 28th day of the month following the end of each quarter:
| Quarter | Period Covered | Standard ATO Due Date | Registered Agent Extension |
|---|---|---|---|
| Q1 | 1 July – 30 September 2026 | 28 October 2026 | 25 November 2026 |
| Q2 | 1 October – 31 December 2026 | 1 March 2027* | 1 March 2027 (Included) |
| Q3 | 1 January – 31 March 2027 | 28 April 2027 | 26 May 2027 |
| Q4 | 1 April – 30 June 2027 | 28 July 2027 | 25 August 2027 |
* Note: The standard Q2 due date (28 February 2027) falls on a Sunday, so the official ATO deadline rolls to Monday, 1 March 2027. Q2 already incorporates a built-in 1-month Christmas holiday extension for all lodgers.
Monthly vs. Annual Reporting Cycles
Monthly Reporting Cycle
Mandatory for businesses with annual GST turnover of $20 million or more. Smaller businesses may choose monthly reporting to manage cash flow. Monthly BAS returns are strictly due on the 21st day of the following month (e.g., July BAS is due 21 August).
Annual Reporting Cycle
Available to businesses voluntarily registered for GST with turnover below $75,000 ($150,000 for non-profits). Annual returns are due by 31 October following the end of the financial year (or 28 February if not required to lodge an income tax return).
ATO Late Lodgement Penalties & General Interest Charge (GIC)
Failing to lodge your BAS on time triggers statutory financial penalties from the ATO under the Failure to Lodge (FTL) penalty system.
Failure to Lodge (FTL) Penalty Units:
For small business entities, FTL penalties are calculated at 1 penalty unit for each 28-day period (or part thereof) that the activity statement is overdue, up to a maximum of 5 penalty units:
- 1 – 28 days late: 1 Penalty Unit
- 29 – 56 days late: 2 Penalty Units
- 57 – 84 days late: 3 Penalty Units
- 85+ days late: Maximum 5 Penalty Units
Important Tax Rule Change: General Interest Charge (GIC) applied by the ATO on late tax balances is non-deductible for income tax purposes. Settling your BAS on time protects your cash flow from unclaimable interest penalties.
What if You Have No Activity During a Quarter?
Even if your business made $0 in sales and incurred $0 in expenses during a reporting period, you are still legally required to lodge a "Nil BAS" by the standard deadline. You can lodge a Nil BAS in seconds using ATO online services or MyGov for sole traders.
Operating in the gig economy? Use our specialized Uber Rideshare GST Calculator to easily split your gross trip fares from platform service fee credits. For general questions, drop us a line via our Contact Page.