BAS explained: what goes on your Business Activity Statement
A simple guide to the Business Activity Statement (BAS) for small businesses: GST, PAYG withholding, PAYG instalments, how often to lodge and common mistakes.
If your business is registered for GST, you lodge a Business Activity Statement (BAS) with the ATO. It reports the tax you've collected and the tax you owe for the period.
What's on a BAS
- GST on sales – the GST you charged your customers.
- GST credits – the GST you paid on business purchases, which you can claim back.
- PAYG withholding – tax you withheld from employees' wages, if you have staff.
- PAYG instalments – prepayments of your own income tax, if the ATO has put you into the instalment system.
- Other items, such as fuel tax credits or wine equalisation tax, if they apply to you.
The difference between what you owe and what you can claim is the amount you pay, or the refund you receive.
How often
- Quarterly – most small businesses. See the 2026–27 BAS due dates.
- Monthly – required for businesses with GST turnover of $20 million or more, and optional for others (useful if you usually get refunds).
- Annually – possible for some small businesses that registered for GST voluntarily.
Cash or accrual
Most small businesses can report GST on a cash basis, meaning you report GST when you're paid or when you pay a bill. On an accrual basis you report it when you issue or receive the invoice. The right choice can help your cash flow.
Common BAS mistakes
- Claiming GST credits without a valid tax invoice.
- Claiming GST on items that don't include GST, such as bank fees, most insurance stamp duty, wages and some fresh food.
- Claiming GST on private purchases, or on the private-use share of a car or phone.
- Forgetting to report GST on the sale of business assets, such as a vehicle.
- Lodging late, which can lead to penalties. Lodge on time even if you can't pay, and set up a payment plan.
We prepare and lodge BAS from $210 + GST, and lodging through us usually gives you extra time for most quarters. Send us a request to get started.
This article is general information only and does not take your personal circumstances into account. It is not financial or tax advice. Tax rules change, so please contact us before acting on it. Information current as at the date above.