- BAS and tax returns serve different purposes. BAS tracks GST and PAYG throughout the year, while your tax return calculates your final income tax position annually.
- If you’re registered for GST, you’ll usually need both. BAS is ongoing, and your tax return is still required at the end of the financial year.
- Staying consistent across both is critical; the ATO cross-checks your BAS and tax return, so errors or mismatches can lead to penalties or reviews.
Most Australian business owners assume tax is a once-a-year job, lodge your return in October, get your refund, and move on. But if you’re running a GST-registered business, the ATO expects more than that.
BAS and tax returns are two separate obligations, different purposes, different timelines, and different triggers. Yet many business owners mix them up, miss one entirely, or assume their tax accountant is handling both when they’re not.
In this guide, we break down the difference between BAS and tax return in Australia, whether your business needs to lodge both, and how the two work together, so nothing slips through the cracks.
Don’t wait until EOFY to think about tax. Keeping your BAS accurate and up to date throughout the year makes your tax return faster, cleaner, and far less stressful.
What’s the difference between BAS and a tax return in Australia?
Not sure which one applies to you or whether you need both? Here’s the side-by-side breakdown at a glance.
Aspect | BAS | Tax return |
What it reports | GST collected & credits, PAYG withholding, PAYG instalments | Total income, deductions, offsets, and net tax owed or refunded |
Who must lodge | Any business registered for GST | Individuals and businesses with a tax return lodgement obligation issued by the ATO |
What triggers it | Crossing the $75K GST turnover threshold | Earning income, running a business, or receiving an ATO lodge notice |
How often | Monthly, quarterly, or annually | Once a year |
Reporting period | Short rolling period (month/quarter) | Full financial year (1 Jul – 30 Jun) |
Tax type covered | Indirect taxes, GST is collected on behalf of the ATO, it’s not your money | Direct tax, income tax on what your business actually earned and kept |
Due date | 28th of the month following each period | 31 October self-lodged; up to 15 May with a registered tax agent |
What happens if you miss it | Failure to Lodge (FTL) penalty and interest charges | Failure to Lodge (FTL) penalty and potential ATO audit flag |
Do they interact? | Yes, PAYG instalments paid via BAS are credited against your tax return liability | Yes, income reported must reconcile with GST figures on your BAS |
Lodged by | Business owner, bookkeeper, or registered BAS agent | Individual, entity, or registered tax agent |
The key takeaway: a BAS keeps you compliant throughout the year. A tax return settles your income tax at the end of it. They’re connected but they are not the same thing, and missing either one has real consequences.
What is a Business Activity Statement (BAS) in Australia?
A Business Activity Statement (BAS) is a form issued by the ATO to GST-registered businesses to report and pay tax obligations throughout the year. This typically includes
- GST collected on sales
- GST credits on purchases
- PAYG withholding (if you have employees)
- PAYG instalments toward your income tax
Most small businesses lodge BAS quarterly. Businesses with turnover above $20 million lodge monthly, while those voluntarily registered below the $75,000 GST threshold may lodge annually.
Want the full picture? Read our complete guide: How to lodge a Business Activity Statement in Australia?
What is a tax return in Australia?
A tax return is an annual report you lodge with the ATO declaring your total income, deductions, and tax already paid for the financial year (1 July to 30 June). Based on this, the ATO calculates whether you owe additional tax or are entitled to a refund.
- Unlike a BAS, a tax return looks at the full picture, your total income, allowable deductions, and any tax already paid throughout the year, including PAYG instalments reported via your BAS.
- Most individuals and businesses lodge annually, with a standard self-lodgement deadline of 31 October.
- Businesses using a registered tax agent may be eligible for later lodgement dates under the ATO lodgement program, depending on their circumstances.
Want the full picture? Read our complete guide: The Complete Guide to Tax Returns in Australia.
Most compliance issues don’t come from tax returns, they start with BAS. Errors in GST reporting, missed lodgements, or incorrect PAYG instalments often flow through and create bigger problems at year-end.
What are the key differences between BAS and a tax return?
The table covered the basics. This is what actually matters, understanding how each obligation works so you can stay on top of both without second-guessing yourself every tax season.
1. They tax completely different things
- GST was never your money to begin with. When you invoice a client and add 10%, that portion belongs to the ATO, you’re simply holding it until your next BAS is due.
- A tax return, on the other hand, focuses on what your business actually earned and kept after expenses.
Two different tax types, two different calculations.
2. They run on completely different timelines
- BAS doesn’t wait for EOFY. You’ll lodge monthly or quarterly, depending on your reporting cycle, so there’s always a deadline coming up.
- A tax return is a once-a-year obligation after 30 June, covering your full financial year.
Missing a BAS deadline doesn’t carry over to your tax return. They operate independently, one doesn’t cover the other.
3. They’re triggered by different requirements
- You must lodge a tax return if you earn income, this applies regardless of your structure or GST status.
- BAS is only required if you’re registered for GST. This typically happens once your turnover reaches $75,000 in a 12-month period ($150,000 for non-profits), or if you register voluntarily.
Below that threshold and not registered? No BAS. But your tax return is still required.
4. They calculate tax in different ways
- BAS is straightforward:
GST collected − GST credits = amount payable or refundable - A tax return takes a broader view:
Total income − allowable deductions = taxable income, which is then taxed at the applicable rate
The two are connected, your tax return should align with what you’ve reported across your BAS lodgements. Discrepancies are a common trigger for ATO reviews.
5. Missing either one has real consequences
- Both BAS and tax returns can attract Failure to Lodge (FTL) penalties and these add up quickly if multiple BAS periods are missed.
- For BAS, the ATO may also apply the General Interest Charge (GIC) on unpaid amounts, compounding daily from the original due date.
Repeated missed lodgements don’t just lead to penalties, they raise compliance flags, which can result in closer scrutiny of your overall tax position, including your annual return.
Do I need to lodge both BAS and a tax return in Australia?
It depends on your business structure and whether you’re registered for GST. Here’s how it breaks down for the most common scenarios.
Do GST-registered sole traders need to lodge BAS and a tax return?
Yes, you need both. You’ll lodge BAS quarterly (or monthly if required) throughout the year, and an individual tax return annually after 30 June. Your business income and expenses are reported through your personal tax return via a Business and Professional Items (BPI) schedule.
Do sole traders under $75,000 need to lodge BAS or just a tax return?
No BAS required, unless you’ve voluntarily registered for GST. If you’re not registered for GST, you generally won’t need to lodge BAS. However, you may still have other ATO obligations depending on your circumstances, such as PAYG instalments or employer reporting obligations. That said, once your turnover approaches $75,000, you’re required to register for GST and BAS obligations kick in from that point.
Do companies need to lodge both BAS and a tax return in Australia?
A GST-registered company lodges BAS throughout the year and a separate company tax return annually. Directors also lodge their own individual tax returns on top of that, so if you’re a director, you’re looking at three separate lodgements: BAS, company tax return, and your personal return.
What happens when a freelancer crosses the $75,000 GST threshold?
As a freelancer, your tax return obligation was already there. But the moment your turnover hits $75,000, GST registration becomes mandatory and with it, BAS. This is the transition point where a lot of sole traders get caught out, often registering late and facing backdated GST obligations.
Do employees without any side income need to lodge BAS or a tax return?
Just an annual tax return. No BAS required.
| Business type | BAS required | Tax return required |
| Sole trader, GST-registered | Yes | Yes |
| Sole trader, under $75K (not registered) | No | Yes |
| Company (GST-registered) | Yes | Yes (company and personal) |
| Freelancer crossing $75K | Yes | Yes |
| Employee, no side business | No | Yes |
The pattern is simple: a tax return applies to almost every business. BAS is an additional requirement that comes with GST registration.
If you’re unsure where your business sits or you’re getting close to the $75,000 threshold, it’s worth getting advice from a qualified tax accountant so you can stay compliant.
How do BAS and tax returns work together?
Think of BAS and your tax return less like two separate tasks and more like two chapters of the same story. Here’s how they connect end to end.
Step 1: You lodge BAS throughout the year
Every quarter (or month), your BAS captures GST collected, GST credits claimed, and any PAYG instalments, prepayments toward your annual income tax bill.
Step 2: Those payments carry forward
The PAYG instalments you’ve paid via BAS don’t disappear at year end. They’re credited directly against your income tax liability when you lodge your tax return, reducing what you owe, or generating a refund if you’ve overpaid.
Step 3: The ATO cross-checks everything
The income reported on your tax return must reconcile with the taxable sales reported across your BAS lodgements for the same financial year. The ATO matches these figures. Discrepancies, even unintentional ones, are a common trigger for reviews and amended assessments.
Step 4: Clean BAS means a cleaner tax return
Errors in your BAS don’t stay contained. Miscoded transactions or missed GST credits flow through and create complications at tax time. Businesses that stay on top of BAS throughout the year consistently have faster, more accurate tax returns.
What are the most common BAS and tax return mistakes?
There’s a lot of confusion around BAS and tax returns and getting it wrong can be costly. Here are some of the most common misconceptions to clear up.
1. “I’ve lodged my tax return, so I’m done for the year.”
Not if you’re GST-registered. Your tax return finalises your income tax for the year, but your BAS obligations continue throughout the year.
Lodging your tax return in October doesn’t mean you’re done, your next BAS deadline is likely just around the corner.
2. “BAS is just a GST form.”
GST is the main component, but it’s not the only one.
Depending on your business, your BAS can also include PAYG withholding, PAYG instalments, and sometimes other obligations like FBT instalments. Treating it as GST-only can lead to underreporting.
3. “I don’t make much profit, so I don’t need to lodge BAS.”
BAS is based on turnover, not profit.
If your business reaches $75,000 in GST turnover, you’re required to register for GST and lodge BAS regardless of whether you’re making a profit or running at a loss.
4. “My tax agent handles my tax return, so my BAS is covered too.”
Not always. BAS agents and tax agents are registered under different categories with the Tax Practitioners Board, although registered tax agents can generally also provide BAS services.
Many firms offer both services, but it’s important to confirm what’s included. If you’re only engaged for an annual tax return, your BAS may not be part of the service.
5. “I can catch up on missed BAS lodgements later.”
Catching up is better than not lodging but it comes at a cost.
The ATO applies Failure to Lodge (FTL) penalties per missed period, and interest may apply on unpaid amounts. The longer you delay, the more it adds up.
When should you get help with BAS and tax returns?
A lot of business owners start out managing both themselves and for simple situations, that’s perfectly fine. But there are clear points where DIY stops being efficient and starts becoming a liability.
It’s probably time to get help if:
- Your turnover is approaching or has crossed the $75,000 GST threshold and you’re not sure what to do next
- You have employees, PAYG withholding, STP reporting, and super obligations add layers that are easy to get wrong
- Your BAS and tax return figures aren’t reconciling and you’re not sure why
- You’ve missed one or more BAS lodgements and penalties are starting to stack up
- You’re operating through a company or trust structure where tax return obligations are more complex
- The ATO has sent you a letter and you’re not sure how to respond
- You’re spending more time on compliance than on actually running your business.
Registering for GST triggers ongoing obligations, not just a one-time change. Once your turnover reaches or is expected to reach $75,000, BAS lodgement becomes part of your regular compliance cycle alongside your annual tax return.
How can Sleek help with BAS and tax returns?
Managing BAS and a tax return separately with different deadlines, different calculations, and different consequences for getting it wrong, is exactly where things start to slip for busy business owners.
Hiring a tax accountant shouldn’t just be about getting forms lodged on time. It should mean someone is across your entire compliance picture, BAS and tax return together, not in isolation.
With Sleek, you get:
- A dedicated accountant who understands the full compliance picture from BAS cycles, tax return obligations, and how the two interact for your specific business structure.
- Registered expertise: Our qualified CPA/CA accountants are registered as both tax agents and BAS agents, so both obligations are covered.
- Maximised, compliant deductions: We help you claim everything you’re legitimately entitled to across your tax return, without crossing ATO lines
- Year-round support: Not just at EOFY, but every quarter when BAS is due and whenever your income, structure, or circumstances change.
- Transparent, upfront pricing: No hourly billing or hidden fees. You’ll know exactly what you’re paying for your BAS and tax return services, so you can plan with confidence.
Stop managing two obligations like they’re unrelated. Talk to a Sleek accountant and get both handled accurately and timely.
Answer a few quick questions and get a personalised recommendation.
450,000
businesses worldwide.
from 4,100+ reviews.
satisfaction rate from
16,000 surveyed clients.
Frequently Asked Questions
What is the main difference between a BAS and a tax return in Australia?
A BAS reports and pays indirect taxes, primarily GST, PAYG withholding, and PAYG instalments to the ATO throughout the year. A tax return is an annual report of your total income, deductions, and net income tax for the full financial year. They cover different tax types, run on different schedules, and are triggered by different circumstances.
Can I lodge my BAS and tax return at the same time?
Generally, no. BAS lodgements follow their own quarterly or monthly cycle throughout the year regardless of when your tax return is due. The one exception is businesses voluntarily registered for GST with turnover under $75,000, they can opt for annual BAS lodgement, which aligns with their tax return deadline. For most businesses though, the two are lodged separately on different schedules.
Do sole traders need to lodge both a BAS and a tax return?
If you’re a sole trader registered for GST meaning your turnover is $75,000 or more, yes, you need both. Your BAS is lodged quarterly (or monthly) throughout the year, and your individual tax return is lodged annually after 30 June. If you’re under the $75,000 threshold and not voluntarily GST-registered, only an annual tax return is required.
