Definition
A Business Activity Statement (BAS) is the Australian Tax Office form used by GST-registered businesses to report and pay multiple tax types over a period. The mandatory section is GST. Optional sections cover PAYG withholding (employer payroll tax withheld from employees), PAYG instalments (the business’s own income tax pre-payments), fringe benefits tax instalments, wine equalisation tax, luxury car tax, and fuel tax credits.
What the BAS means in practice
For most Australian SMBs, the BAS is the single most important compliance deadline of the quarter. It carries the GST liability, the PAYG withholding for employees, and the PAYG instalment for the business’s own income tax. Missing a BAS produces a late lodgement penalty (one penalty unit, currently AUD 330, per 28 days late) and, more painfully, interest on the unpaid GST at the General Interest Charge rate.
The bookkeeping workload behind a BAS is concentrated in the last week of the period: reconciling the bank account to the books, confirming every supplier invoice has a tax invoice that supports the input tax credit claim, posting payroll if the platform does not run STP, and clearing any GST control account differences. Anything that does not reconcile becomes a manual journal in the BAS prep file.
A practical example: a Sydney consultancy with AUD 600,000 turnover lodges quarterly. For Q1 (Jul-Sep) they collected AUD 60,000 of GST on sales and paid AUD 8,000 of GST on inputs. They also withheld AUD 15,000 of PAYG from staff and have a PAYG instalment of AUD 5,000 against their own income tax. The BAS shows AUD 60,000 minus AUD 8,000 plus AUD 15,000 plus AUD 5,000 equals AUD 72,000 payable, due 28 October.
How the BAS works by country
Australia
Every GST-registered business lodges a BAS. The default cycle is quarterly for SMBs under AUD 20 million turnover. Monthly is mandatory above AUD 20 million and is an option for businesses regularly in a refund position (so they get the refund sooner). Annual BAS is available for voluntarily-registered businesses below the AUD 75,000 turnover threshold.
The 2026 standard due dates are:
| Quarter | Period | Due (self-lodge) | Due (BAS agent) |
|---|---|---|---|
| Q1 | Jul-Sep 2026 | 28 Oct 2026 | 25 Nov 2026 |
| Q2 | Oct-Dec 2026 | 28 Feb 2027 | 27 Mar 2027 |
| Q3 | Jan-Mar 2027 | 28 Apr 2027 | 26 May 2027 |
| Q4 | Apr-Jun 2027 | 28 Jul 2027 | 25 Aug 2027 |
Q2 carries a four-week holiday extension that the ATO grants every year. Businesses using a registered BAS agent get a further ~four-week extension automatically on the BAS Agent Lodgment Program.
United Kingdom
The United Kingdom does not have a BAS. The equivalent indirect-tax return is the quarterly UK VAT return submitted under MTD. PAYE is handled separately under Real Time Information (RTI), with FPS submissions on or before each payday.
Canada
Canada does not have a BAS. GST/HST is on its own return at frequency determined by revenue: annual under CAD 1.5 million, quarterly between CAD 1.5 million and CAD 6 million, monthly above. Payroll source deductions go on a PD7A remittance form on a separate calendar.
New Zealand
New Zealand does not have a BAS. GST is reported on GST101A at the registered frequency (monthly, 2-monthly, or 6-monthly). Payroll uses payday filing (called Employment Information returns) submitted to IRD each pay run.
Singapore
Singapore does not have a BAS. GST is reported on F5 quarterly returns. CPF contributions for employees are submitted electronically to the CPF Board monthly by the 14th of the following month.
Related terms
The BAS pulls together several tax categories that each have their own glossary entries:
- GST is the main section of the BAS.
- A tax invoice is what supports each input tax credit claim on the GST section.
- PAYG covers both the PAYG Withholding (employee tax) and PAYG Instalment (business income tax) sections.
- Single Touch Payroll overlaps with the PAYG Withholding section.
- FBT instalments are an optional section for employers with fringe benefits liability.
See also
For the full Australian BAS lifecycle including registration, calculation methods, and lodgement, see the Australian GST and BAS guide.
FAQ
See the answered questions above for 2026 due dates, nil-BAS lodgement, and the difference between BAS and IAS.