A Business Activity Statement — the BAS — is the form lodged with the ATO to report your GST obligations. If your business is registered for the Goods and Services Tax, you must lodge one. No exceptions, including periods when you had no activity.
Many business owners find the BAS genuinely stressful, particularly in the early years of running a business. The deadlines are tight, the consequences of errors accumulate, and the form itself can be confusing if you are not familiar with the underlying concepts. This guide explains what the BAS covers, what the current due dates are, and what the sensible approach to managing the process looks like.
Who needs to lodge a BAS?
Any business registered for GST must lodge a BAS. GST registration is compulsory once your annual turnover reaches $75,000. Ride-sharing drivers and taxi operators must register from their first dollar of turnover. Once registered, the obligation to lodge does not stop, even in quarters when the business earns nothing.
What a BAS actually reports
GST collected on sales
Once registered for GST, you add 10 per cent to the price of most goods and services you supply. That GST is collected on behalf of the ATO — it is not your revenue. Each BAS period, you report the total GST collected and remit it to the ATO.
GST credits on purchases
The other side of the equation is input tax credits. GST-registered businesses can claim back the GST included in the price of eligible business purchases. The difference between what you collected and what you can claim determines whether you owe the ATO money or are owed a refund.
PAYG withholding
If you employ staff, you withhold income tax from their wages each pay period. Those withheld amounts are reported on the BAS and remitted to the ATO on the same schedule as your GST obligations, or monthly if your annual withholding exceeds $25,000.
How often do you need to lodge?
Most small businesses lodge quarterly. Businesses with a GST turnover of $20 million or more must lodge monthly. Some businesses with very low turnover can elect to lodge annually. Your frequency is set when you register for GST, but can be changed.
BAS due dates for 2025-26
For quarterly lodgers, the standard due dates are:
- Quarter 1 (July to September 2025): 28 October 2025
- Quarter 2 (October to December 2025): 28 February 2026
- Quarter 3 (January to March 2026): 28 April 2026
- Quarter 4 (April to June 2026): 28 July 2026
Businesses lodging through a registered tax agent or BAS agent under the Tax Agent Lodgement Program may qualify for a two-week extension on each deadline. This extension applies automatically — the client does not need to apply for it individually.
The BAS errors that attract ATO attention
These are the patterns the ATO's compliance team looks for:
- Claiming input tax credits on private or non-business expenses
- Understating income by excluding cash sales or income from secondary business activities
- Incorrectly classifying GST-free or input-taxed supplies as fully taxable
- Lodging without reconciling your BAS figures against your accounting software first
- Missing the lodgement deadline and accumulating failure-to-lodge penalties
The failure-to-lodge penalty for a small business is currently $313 per penalty unit. Penalties apply per BAS period and accumulate across quarters. A few missed deadlines can result in several thousand dollars in penalties within a single financial year.
Payday super: a major change from 1 July 2026
From 1 July 2026, employers must pay superannuation contributions at the time wages are paid rather than quarterly. This is a significant shift for any business that currently manages super on a quarterly cycle. Businesses that are not prepared face penalties from the first missed payday.
Your payroll software needs to be updated before the deadline, and your cash flow planning needs to account for super as a fixed cost on every pay run rather than a quarterly one. Lodge with P&D Accountants is currently advising all business clients with employees on the transition. Contact us if you need a review of your payroll setup.
Working with a registered tax agent or BAS agent
A registered tax agent or BAS agent reviews your figures before lodgement, catches errors, identifies credits you may have missed, and takes legal responsibility for the accuracy of the return. If the ATO queries a lodgement that an agent prepared, the agent can respond and represent you directly.
P&D Accountants is a registered tax agent. We prepare and lodge BAS returns for sole traders, companies, partnerships, and trusts across Australia. We also send automated deadline reminders at 30, 14, and 7 days before each due date so nothing slips through.
Need help with your BAS?
Let a registered tax agent prepare, review, and lodge your BAS — with automated reminders so you never miss a deadline.
Call us on 0468 070 010Frequently asked questions
What is the BAS due date for Quarter 4 of 2025-26?
The due date for the April to June 2026 quarter is 28 July 2026. Businesses lodging through a registered agent may qualify for an extended due date under the Tax Agent Lodgement Program.
What happens if I lodge my BAS late?
The ATO issues a failure-to-lodge penalty of $313 per penalty unit. The number of penalty units increases the longer the lodgement remains outstanding. Penalties can accumulate to thousands of dollars across multiple overdue periods. A registered tax agent can often apply to have penalties remitted in part where there is a reasonable explanation.
Can I lodge my BAS myself?
Yes. You can lodge through the ATO's Business Portal or through accounting software connected to the ATO's SBR channel. However, self-lodgement offers no extension to the standard deadline, no professional review before lodgement, and no representation if the ATO queries the return.
Do I need to lodge a BAS if my business had no income for the quarter?
Yes. Once registered for GST, you must lodge a BAS for every period, even if your activity was nil. A nil BAS is straightforward to complete but must still be lodged by the due date.