Small business guide
What is a BAS? Business activity statements and 2026-27 due dates
The short answer
A BAS (business activity statement) is the form a business uses to report and pay its GST, PAYG withholding from wages, PAYG instalments and a few other taxes to the ATO1. Most small businesses lodge one each quarter; the next is due 28 October 2026, or 25 November 2026 through a registered agent23.
What goes on a BAS
- GST: the GST you charged on sales, less the GST you paid on business purchases1.
- PAYG withholding: tax you took out of employees' wages1.
- PAYG instalments: payments towards your own or your company's income tax for the year1.
- Less often: fringe benefits tax instalments, luxury car tax and wine equalisation tax1.
Quarterly BAS due dates, 2026-27
| Quarter | If you lodge yourself | Through a registered agent |
|---|---|---|
| July to September 2026 | 28 October 20262 | 25 November 20263 |
| October to December 2026 | 28 February 20272 | 28 February 20273 |
| January to March 2027 | 28 April 20272 | 26 May 20273 |
| April to June 2027 | 28 July 20272 | 25 August 20273 |
Good to know: The agent dates apply to electronic lodgment by a registered tax or BAS agent3. The December quarter has no agent extension because it already includes an extra month2.
Hand the BAS to someone else
Hear from up to three registered BAS agents and bookkeepers who cover your postcode, and get the agent lodgment dates. Free, no obligation.
Monthly BAS
A monthly BAS is due on the 21st of the following month. It is compulsory once GST turnover reaches $20 million, and some smaller businesses choose it2.
Who can do your BAS for you
Generally, only a registered tax agent or registered BAS agent can charge a fee to prepare or lodge a BAS45. Both are on the Tax Practitioners Board's public register, which you can search for free5.
Many bookkeepers are registered BAS agents. A bookkeeper who is not registered can keep your books but cannot charge you to lodge the BAS. For how the roles differ, see accountant vs bookkeeper.
FIZO checks tax agents and BAS agents against the TPB register every month and shows the result on their listing.
If you cannot pay on time
The ATO's advice is to lodge on time anyway and contact it before the due date6. See what to do about an ATO debt.
Who can help
Questions people ask
When is the next BAS due?
The July to September 2026 quarter is due 28 October 2026 if you lodge yourself2, or 25 November 2026 if a registered agent lodges it electronically3.
What is the difference between a BAS agent and a tax agent?
Both can prepare and lodge a BAS. Only a tax agent can prepare and lodge income tax returns4.
Does a bookkeeper have to be registered to do my BAS?
To charge a fee for preparing or lodging a BAS, generally yes: they need to be a registered BAS agent or tax agent45.
Do I need to lodge a BAS if I am not registered for GST?
You may still need one if you withhold tax from wages or pay PAYG instalments, as those are reported on a BAS too1.
Talk it through with a professional
Tell us once and hear from up to three bookkeepers who cover your postcode. Free, no obligation, and FIZO never recommends one over another.
Sources
- ATO, Business activity statements (BAS)
- ATO, Due dates for lodging and paying your BAS
- ATO, Registered agent lodgment program: activity statements 2026-27
- Tax Practitioners Board, Finding and using a tax practitioner
- Tax Practitioners Board, Public register
- ATO, What if you can't lodge and pay on time
FIZO is a directory, not a tax or legal adviser. Rules and thresholds change: check the source, or ask a registered professional about your own business.