What is a business activity statement?
A business activity statement is the form businesses registered for GST submit to the ATO to report and pay tax obligations, including GST, PAYG withholding and PAYG instalments. If you need to lodge BAS, this is the core ATO report that keeps your indirect tax and employer reporting on track.
The ATO says approximately 2.7 million small businesses registered for GST are required to report through BAS. That scale explains why BAS lodgement is such a regular pressure point for Australian businesses.
If you are still getting familiar with the basics, Payroller’s guide to What is a BAS? is a useful starting point.
What taxes does a BAS cover?
A BAS may include:
- GST collected on sales
- GST credits claimed on business purchases
- PAYG withholding from employee wages
- PAYG instalments for your business income tax
- FBT instalments, where registered
- Other taxes such as wine equalisation tax or luxury car tax, where they apply
Not every business activity statement includes every item. The ATO only includes sections that match your registrations.
Who administers the BAS and why does it exist?
The ATO administers BAS to collect tax information during the year, rather than waiting until income tax returns are lodged. This gives businesses a structured way to report, file and pay obligations on a monthly, quarterly or annual lodgement cycle.
How does a BAS differ from a tax return?
A BAS is not the same as an income tax return. A BAS reports activity-based taxes such as GST and PAYG withholding. A tax return reports taxable income, deductions and final income tax payable. This distinction matters for sole traders and first-time business owners, who often assume one replaces the other.
Who needs to lodge a BAS?
Any business registered for GST with an ABN must lodge a BAS. The GST registration threshold is $75,000 in annual turnover for most businesses and $150,000 for non-profits. Once registered, BAS lodgement is mandatory, even if your sales are lower in a later period.
The Australian Bureau of Statistics reports over 2.5 million actively trading businesses in Australia, with construction, professional services and retail among the largest categories. These sectors often have regular GST activity and payroll obligations, which makes BAS discipline a practical business habit.
What is the GST registration threshold?
You must register for GST if your annual turnover reaches the relevant threshold. You can also register voluntarily while below the threshold. That can make sense if you want to claim GST credits on purchases, but it also means you must lodge a business activity statement when required by the ATO.
Do sole traders need to lodge a BAS?
Yes, if they are registered for GST. The need to lodge BAS as a sole trader depends on GST registration, not whether you operate through a company. A sole trader with no employees may only report GST. A sole trader with staff may also report PAYG withholding.
How do ABN and GST registration affect your obligations?
Your ABN identifies your business to the ATO. GST registration creates the BAS obligation. If you employ staff, you also need the right ATO setup for payroll and Single Touch Payroll. Payroller’s guide to registering with the ATO as an employer walks through that step before payroll reporting begins.
What is actually included in a BAS?
A BAS can include several tax obligations depending on your business structure and ATO registrations. The most common components are GST collected and paid, PAYG withholding from employee wages and PAYG instalments on business income. Before you lodge BAS, check which labels appear on your form so you only report what applies to your business.
How is GST calculated and reported?
GST is usually calculated as:
- GST collected on taxable sales
- Minus GST credits on creditable business purchases
- Equals the net GST amount payable or refundable
For example, a retail store that charges GST on sales and pays GST on stock purchases reports both sides. If GST collected is higher than credits, the business pays the difference. If credits are higher, it may receive a refund.
What is the difference between PAYG withholding and PAYG instalments?
This is one of the most common BAS mix-ups.
PAYG withholding is tax withheld from employee wages. If you run payroll, you withhold amounts from employees and report them to the ATO.
PAYG instalments are prepayments toward your own business or investment income tax. They are based on your income and ATO instalment rate or amount.
A small retail business with employees will typically report GST and PAYG withholding. A consultant operating as a sole trader with no employees may report GST and PAYG instalments, depending on what the ATO has issued.
When does FBT, wine equalisation tax, or luxury car tax apply?
These only apply to certain businesses. FBT can apply if you provide fringe benefits to employees. Wine equalisation tax applies to some wine producers, wholesalers and importers. Luxury car tax applies to certain high-value vehicle sales or imports.
The practical rule is simple: **do not assume every BAS label applies to you. Report the labels the ATO has issued based on your registrations.
How do you lodge a BAS, step by step?
There are three main ways to lodge a BAS: through Online Services for Business via myGovID, through a registered tax or BAS agent, or through ATO-integrated accounting or payroll software. The ATO encourages digital lodgement, and paper forms are being phased out for many businesses.
The ATO’s Online Services for Business is the main digital path for activity statements. If you want to lodge BAS online, this is usually the place to start.
How to lodge a BAS through Online Services for Business
To lodge BAS online through the ATO portal:
- Set up myGovID** on your device.
- Link your myGovID to your ABN using Relationship Authorisation Manager.
- Log in to Online Services for Business.
- Go to **Activity statements.
- Select the activity statement you need to complete.
- Enter your GST, PAYG and other required amounts.
- Review the figures against your records.
- Submit the BAS.
- Save the receipt and payment reference details.
This method suits business owners who manage their own records and want direct control over lodgement.
How to lodge a BAS through accounting or payroll software
ATO-integrated software can reduce manual entry. Accounting software usually tracks GST from sales and purchases. Payroll software such as Payroller helps capture PAYG withholding through STP reporting, which supports BAS preparation.
If you lodge BAS online through software, the value is in the workflow: fewer spreadsheets, fewer duplicated figures and a clearer audit trail. BAS is also part of wider tax compliance for businesses, so choosing software that connects payroll and reporting can save time each cycle.
When should you use a registered BAS agent?
A registered BAS agent can lodge on your behalf and may receive extended lodgement dates. This can suit:
- Retail employers with high transaction volumes
- Construction businesses managing contractors, employees and GST on materials
- Professional services firms with mixed income, payroll and instalment obligations
- Payroll professionals managing several client files
You can still use Payroller alongside an agent. The cleaner your payroll and STP records are, the faster your agent can review and submit.
What are the deadlines for lodging a BAS?
BAS deadlines depend on your reporting cycle: monthly, quarterly or annual. Quarterly lodgers make up many small businesses, with due dates usually falling on the 28th day of the month after each quarter ends. The December quarter has a later due date of 28 February to account for the holiday period.
If you lodge BAS late, penalties can apply, so the safest approach is to set your process around BAS due dates rather than waiting for reminders.
What are the standard quarterly and monthly due dates?
Common quarterly BAS due dates are:
- July to September quarter: 28 October
- October to December quarter: 28 February
- January to March quarter: 28 April
- April to June quarter: 28 July
Monthly lodgers usually report by the 21st day of the following month. Annual lodgement applies to some voluntary GST registrants and lower-turnover businesses.
Is there a deadline extension for businesses using a BAS agent?
Businesses using a registered BAS agent may receive extra time to lodge. This is one reason many growing businesses move from DIY lodgement to agent-supported reporting once payroll, GST and cash flow become harder to manage in-house.
How to set up reminders so you never miss a deadline
Build your BAS due dates into your calendar before the year starts. A simple rhythm works best:
- Set a reminder two weeks before each due date
- Set a second reminder one week before the due date
- Book a recurring BAS prep block to reconcile payroll, bank and GST records
- Check that your ATO portal, myGovID or software access still works before lodgement week
The goal is to remove last-minute pressure.
What are the penalties for getting your BAS wrong or late?
Missing a BAS deadline or lodging inaccurate figures carries real financial cost. The ATO’s failure to lodge penalty is one penalty unit for every 28 days a BAS is overdue, up to five penalty units for small entities. At $313 per unit, those costs rise quickly.
If you need to lodge BAS, time and accuracy both matter. A late BAS can create penalty exposure. An incorrect BAS can lead to ATO review, interest or amended amounts payable.
How much is the failure to lodge penalty?
Using the ATO-listed penalty unit amount:
- Up to 28 days late: one penalty unit, $313
- 29 to 56 days late: two penalty units, $626
- 57 to 84 days late: three penalty units, $939
- 85 days or more late: the small-entity cap can be reached
That is why a missed BAS should be handled quickly, not left for the next quarter.
What penalties apply for incorrect reporting?
Incorrect reporting can create tax shortfalls, interest charges and ATO follow-up. Common triggers include GST credits claimed incorrectly, sales omitted from GST reporting and PAYG withholding figures that do not match payroll records.
The ATO has also reported a small business tax performance gap of approximately $11.2 billion, which is one reason GST accuracy and small business reporting receive close attention.
How does the ATO’s compliance focus affect small businesses?
The practical takeaway is simple: **clean records reduce risk. Reconcile before lodgement, keep source documents and use systems that create an audit trail. If you process payroll, STP-enabled payroll software helps keep PAYG withholding figures aligned with what has already been reported.
What are the most common mistakes when lodging a BAS?
The most common BAS mistakes are GST coding errors, confusing PAYG withholding with PAYG instalments and misreporting totals because records are not reconciled. Most of these errors are preventable with a simple process and software that reduces manual handling.
When you lodge BAS, your figures should match the story in your bank, payroll and accounting records. If those records do not line up, fix the source before submitting.
What GST coding errors should you watch for?
GST errors often come from coding purchases the wrong way. For example, claiming a GST credit on a purchase from a supplier that is not registered for GST can trigger ATO questions.
Watch for:
- Purchases coded as GST-inclusive when no GST was charged
- Private expenses claimed as business purchases
- Bank fees, wages and some taxes coded incorrectly
- GST claimed without a valid tax invoice
A quick GST review before lodgement can catch many of these issues.
How does poor record-keeping lead to BAS mistakes?
Poor records force guesswork. Guesswork leads to wrong figures. The better process is to reconcile before you lodge, not after.
Before submitting:
- Match bank transactions to sales and expenses
- Check payroll totals against STP reports
- Review unpaid invoices and bills if you report on an accrual basis
- Save tax invoices for creditable purchases
What are the most overlooked line items on a BAS?
PAYG withholding is often overlooked when payroll is handled separately from bookkeeping. Payroller helps by recording payroll and STP data in one place, which reduces the need to manually cross-check wage records when preparing BAS figures.
Other overlooked items include GST adjustments, cancelled invoices and large asset purchases.
How do you correct a BAS after it has been lodged?
If you find an error after lodgement, you can correct it either on a later BAS, where ATO rules allow, or by lodging a revised activity statement through the ATO portal or your BAS agent. Amending a BAS is common, and the process is much easier when your records show what changed and why.
For many small GST errors, the ATO allows correction on the next BAS if the net GST error is under the relevant threshold.
When can you correct an error on your next BAS?
Small GST errors can often be corrected in the next reporting period rather than through a formal revision. For many small businesses, the current net GST error threshold is $10,000.
This is useful for practical issues such as:
- A purchase invoice entered after lodgement
- A GST code corrected after review
- A small sales adjustment found during reconciliation
Keep a note explaining the correction, the amount and the reporting period affected.
How to lodge a revised activity statement through the ATO portal
If amending a BAS directly, log in to Online Services for Business, go to activity statements, select the lodged statement and choose the revision option. Update the labels that need correction, review the net result and submit the revised activity statement.
If you use software, keep the amended report or change log with your BAS records.
How to contact the ATO for assistance with amendments
If the correction does not fit the simple correction rules, use the ATO contact options in Online Services for Business or work through your BAS agent. The best preparation is a clear audit trail: original figures, corrected figures, dates and supporting documents.
How can Payroller help you lodge a BAS more efficiently?
Payroller is built for Australian small businesses and payroll professionals who need compliance without hours of manual reporting. By connecting payroll data to your ATO obligations, Payroller reduces the manual work involved in BAS preparation and helps you lodge BAS with more accurate PAYG withholding figures.
That matters because payroll is one of the easiest areas to misreport when wage records, STP submissions and BAS worksheets live in separate places.
How does Payroller connect payroll data to BAS preparation?
Payroller’s STP reporting captures payroll details each pay run, including PAYG withholding. When BAS time comes around, you are not rebuilding wage tax figures from scratch.
For a retail employer with casual staff, that means less time checking payslips against spreadsheets. For a construction business with changing crews, it means payroll data stays more consistent across reporting periods.
What features does Payroller offer for compliance and reporting?
Payroller supports:
- STP reporting to the ATO
- PAYG withholding tracking through payroll
- Employee payroll records in one system
- Reports that support BAS preparation
- Automation that reduces repetitive manual entry
- Workflows for employers and agents
If you are managing payroll for a team and want BAS preparation to be less of a monthly headache, Payroller is worth exploring.
How do agents use Payroller to help clients with BAS?
Agents can manage payroll and compliance workflows across multiple clients from one platform. That helps when clients have different pay cycles, reporting needs and BAS due dates.
Payroller also supports agent workflows such as registering clients with the ATO as an agent and gives professionals tools to help clients with tax compliance. The result is less chasing, cleaner records and faster BAS preparation.
What are the best practices for staying on top of BAS lodgement?
The businesses that stay calm at BAS time reconcile records regularly, use software that automates PAYG and GST tracking, and treat BAS preparation as an ongoing routine rather than a last-minute task. If you need to lodge BAS, the best system is one that keeps records ready before the due date arrives.
Payroller fits into that routine by keeping payroll and STP data current across each pay run.
How to build a BAS preparation checklist
Use this checklist before each lodgement:
- Reconcile bank accounts
- Check sales totals against accounting records
- Review GST coding on purchases
- Check payroll figures against STP reports
- Review PAYG withholding totals
- Look at large or unusual purchases
- Check any GST adjustments
- Make sure myGovID, ATO portal or software access works
- Save reports and receipts after lodgement
A checklist reduces missed items and makes the process repeatable.
Why regular bookkeeping makes BAS lodgement faster
Weekly bookkeeping beats quarterly cleanup. When transactions are coded as they happen, BAS preparation becomes a review task rather than a rescue job.
A good rhythm is:
- Process receipts weekly
- Reconcile bank accounts at least monthly
- Review payroll after each pay run
- Set a “BAS prep week” before each due date
How automation and STP reduce your BAS workload
Automation reduces the most error-prone steps: retyping payroll figures, matching wage tax manually and hunting through old records. STP also means payroll reporting is already flowing to the ATO throughout the period.
When payroll software and accounting software work together, BAS preparation becomes faster, more accurate and easier to trace.
Lodging a BAS does not need to be complicated, but it does need to be consistent. The real pressure for most businesses is time and accuracy: getting payroll, GST and ATO reporting to line up before the deadline.
Payroller helps by connecting payroll data, automating PAYG reporting through STP and giving employers and agents a cleaner way to prepare BAS figures. That means fewer manual checks, fewer avoidable errors and a smoother compliance routine.
Try Payroller free today and spend less time on compliance, more time on your business.