Updated October 2026
A business activity statement (BAS) is the form a GST-registered business lodges with the ATO, usually every quarter, to report and pay GST, PAYG withholding from wages and PAYG instalments. It shows GST collected on sales, less GST paid on purchases, plus tax withheld from staff.
If you would rather have it prepared and lodged for you, see our registered BAS agent services.
For Australian businesses, managing tax obligations is a critical part of staying compliant and financially healthy. One of the most important tools in this process is the Business Activity Statement (BAS). Whether you're a small business or an established company, understanding BAS is essential for seamless tax reporting and compliance with the Australian Taxation Office (ATO).
In this detailed guide, we’ll explore what a BAS is, why it matters, how to prepare it, and tips for streamlining the BAS process to save time and avoid costly mistakes.
A Business Activity Statement (BAS) is a form submitted to the ATO by registered businesses to report their tax obligations, including Goods and Services Tax (GST), Pay As You Go (PAYG) withholding, PAYG instalments, Fringe Benefits Tax (FBT) instalments, and other taxes. It’s a snapshot of your business’s financial activity over a specific period, typically monthly or quarterly, and is used to calculate how much tax you owe or are owed by the ATO.
The BAS process is mandatory for businesses registered for GST. You must register for GST once your GST turnover reaches $75,000 (or $150,000 for non-profit organisations), and taxi and ride-sourcing drivers must register regardless of turnover. That means most established Australian businesses deal with BAS regularly.
Take our free interactive BAS compliance test here.
The BAS is more than just a tax form. It’s a cornerstone of financial compliance. Here’s why it’s critical:
Not every business needs to lodge a BAS. Here’s who’s required:
If you’re unsure whether your business needs to lodge a BAS, check your GST registration status in ATO Online services for business or consult a registered BAS agent.
The frequency of BAS lodgement depends on your business’s size and ATO requirements:
Quarterly reporting is the default for businesses under the $20 million threshold, which is why it is the most common cycle for small businesses.
We have an interactive BAS deadline calculator here.
A BAS typically includes the following sections, depending on your business’s tax obligations:
The complexity of your BAS depends on your business structure and activities. For example, a sole trader with simple transactions may only report GST, while a company with employees will include PAYG withholding and instalments.
Preparing a BAS can feel daunting, but with the right approach, it’s manageable. Here’s a step-by-step guide:
Maintain up-to-date financial records using accounting software like Xero, MYOB, or QuickBooks. Track:
For GST reporting, you can use:
Use your accounting software or manual records to calculate:
Use our free GST calculator here
For simpler BAS and more basic calculations, check our BAS calculator here
You can lodge your BAS through:
If you owe tax, pay by the due date using BPAY, EFT, or another ATO payment option, and allow up to 4 business days for the payment to reach the ATO. If you’re due a refund, the ATO’s 2026-27 service commitment is to finalise 95% of electronically lodged activity statements within 10 business days.
Even experienced business owners can make BAS errors. Here are pitfalls to watch for:
Using a BAS agent or cloud accounting software can reduce these risks, because figures are reconciled before lodgement and deadlines are tracked for you.
For many Australian businesses, outsourcing BAS preparation to a registered BAS agent is a game-changer. Benefits include:
To find a registered BAS agent, visit the Tax Practitioners Board (TPB) website or ask for recommendations within your industry like Scale Suite.
Managing your Business Activity Statement doesn’t have to be a headache. By staying organised, using reliable accounting software, and considering a BAS agent, you can ensure compliance, avoid penalties, and keep your business running smoothly. Whether you’re a small business lodging quarterly or a larger enterprise with monthly BAS obligations, understanding the BAS process is key to financial success in Australia.
Ready to simplify your BAS lodgement? Contact a registered BAS agent or explore cloud accounting solutions tailored for Australian businesses. Don’t let BAS stress hold you back. Take control of your tax obligations today!
BAS, topic by topic
An illustrative quarter for a services business that is registered for GST and employs staff:
Amount payable to the ATO: 1A less 1B, plus W2.
$20,000 less $8,000 plus $21,000 = $33,000.
The W2 figure is illustrative. Your own withholding comes from your payroll reports.
You lodge a BAS if you are registered for GST. The ATO issues one for each reporting period once you register, and you must lodge it even if you have nothing to report. Businesses that are not registered for GST but withhold tax from wages lodge an instalment activity statement instead. See when to register for GST for the $75,000 threshold.
A Business Activity Statement (BAS) is a form submitted to the Australian Taxation Office (ATO) by registered businesses to report tax obligations, including Goods and Services Tax (GST), Pay As You Go (PAYG) withholding, PAYG instalments, Fringe Benefits Tax (FBT), and other taxes. It provides a snapshot of a business's financial activity over a specific period, typically monthly or quarterly, and is used to calculate tax owed or refunds due from the ATO. BAS is mandatory for businesses registered for GST, which applies to most Australian businesses with an annual turnover of $75,000 or more (or $150,000 for non-profit organisations).
BAS is essential for financial compliance, GST reporting, and managing PAYG obligations. It ensures accurate calculation of net GST liability or refunds, helps avoid ATO penalties and interest, and supports better cash flow management by providing timely access to refunds.
Businesses registered for GST (GST turnover of $75,000 or more, or $150,000 for non-profits) must lodge a BAS. This includes businesses with PAYG obligations, such as withholding tax from employee wages or paying instalments on business income tax. Taxi and ride-sourcing drivers must register for GST regardless of turnover. Businesses below the threshold can voluntarily register, which also requires BAS lodgement.
Lodgement frequency depends on business size and ATO requirements. Most small to medium businesses (GST turnover under $20 million) lodge quarterly, with deadlines on 28 October (Q1: July to September), 28 February (Q2: October to December), 28 April (Q3: January to March), and 28 July (Q4: April to June). Businesses with GST turnover of $20 million or more, or those directed by the ATO, lodge monthly by the 21st of the following month. Voluntarily registered businesses under $75,000 can report annually, generally by 31 October.
A BAS includes sections for GST (for example, G1: total sales, 1A: GST collected, 1B: GST paid on purchases), PAYG withholding (W1 to W5: wages and amounts withheld), PAYG instalments (T labels: prepayments of income tax), and other taxes like FBT instalments, Wine Equalisation Tax (WET), or Luxury Car Tax (LCT) if applicable. The content varies by business structure and activities.
To prepare a BAS: (1) Maintain accurate records of sales, expenses, wages, and transactions using software like Xero, MYOB, or QuickBooks. (2) Choose a GST method (full reporting, Simpler BAS for GST turnover under $10 million, or GST instalments for eligible businesses under $10 million). (3) Calculate figures for GST, PAYG, and other taxes, double-checking for accuracy. (4) Lodge via ATO Online services for business, myGov, integrated accounting software, or a registered BAS agent. (5) Pay any owed tax by the due date, or receive your refund once the ATO finalises the statement.
Common errors include incorrect GST calculations (for example, confusing GST-free and taxable sales), missing deadlines (a failure to lodge penalty of $364 per 28 days overdue from 1 July 2026, up to $1,820 for small businesses), claiming invalid input tax credits (for example, for personal or non-allowable expenses), and underreporting PAYG withholding. Using a BAS agent or cloud software can help.
A BAS agent like Scale Suite provides expertise in ATO requirements, saves time on paperwork, gives you access to extended lodgement dates for most quarters, and supports you during ATO reviews. To find one, check the Tax Practitioners Board (TPB) register.
Scale Suite is a Sydney-based provider of outsourced finance teams and fractional CFO services for Australian SMEs. We deliver weekly bookkeeping, payroll, BAS/IAS lodgement, cashflow reporting, management accounts, and strategic fractional CFO oversight, all as a fully embedded team that works inside your business.
CA-qualified, Xero Certified, and registered BAS Agents (BAS agent number 26298194), we replace fragmented bookkeepers and once-a-year accountants with one responsive finance function at a fraction of the cost of full-time hires. We serve growing businesses across Australia, with packages starting from $1,500 per month and no lock-in contracts.
If you would rather not do it yourself, our registered BAS agent services prepare and lodge BAS for Australian businesses.
We review and check articles on a periodic basis, and at the time of writing this information was up to date from our assessment.
Scale Suite is a Sydney-based provider of outsourced finance and HR services for Australian SMEs. We deliver bookkeeping, financial reporting, payroll processing, fractional CFO support, recruitment, employee onboarding, people and culture support, and fractional HR oversight, all as a fully embedded team that works inside your business.
Employment Hero Gold Partner, CA-qualified, and Xero Certified, we replace fragmented finance and HR processes with one responsive, senior-level function at a fraction of the cost of full-time hires. We serve growing businesses across Sydney, Melbourne, Brisbane, Adelaide, and Perth, with packages starting from $1,500 per month and no lock-in contracts.
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We will review your current finance setup, compare the full cost of an internal hire against our embedded team, and show you exactly what your finance function should cost at your stage of growth.
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