Business Activity Statement (Australia): Complete Guide for 2025

What Is a Business Activity Statement (BAS)?

In Australia, the Business Activity Statement (BAS) is a government form issued by the Australian Taxation Office (ATO). It’s the main way businesses report and pay taxes such as GST, PAYG withholding, PAYG instalments, and FBT.

Put simply, BAS acts as a snapshot of a business’s tax obligations over a given period. If your business is registered for Goods and Services Tax (GST), you’ll almost certainly be required to lodge a BAS.

The ATO first introduced BAS in 2000 alongside the GST system. Since then, it has become a key compliance tool for businesses of all sizes — from sole traders to large corporations.

Why BAS Matters for Australian Businesses

Filing BAS isn’t just about ticking a compliance box. Here’s why it matters:

• Keeps businesses tax-compliant – Lodging BAS ensures your business stays on the ATO’s good side.

• Avoids financial penalties – Late or incorrect submissions can lead to hefty fines.

• Helps track cash flow – BAS reporting shows how much GST you’ve collected versus how much you can claim back.

• Builds credibility – A track record of timely lodgements demonstrates professionalism and reliability.

Think of BAS as both an obligation and an opportunity: while mandatory, it also gives businesses valuable insight into their financial position.

Who Needs to Lodge a BAS?

Not every business in Australia is required to lodge BAS. The main factor is GST registration.

GST-registered businesses

Any business with an annual turnover of $75,000 or more (or $150,000 for non-profits) must register for GST and lodge BAS.

Sole traders and partnerships

If you’re a sole trader or part of a partnership earning above the GST threshold, you’ll also need to lodge BAS.

Companies and trusts

Registered companies and trusts meeting the turnover requirement are automatically required to submit BAS.

If you’re unsure, the ATO provides a business eligibility tool to check your obligations.

Key Components of a BAS

A BAS form usually includes several sections depending on your business setup:

Goods and Services Tax (GST) reporting

Report GST collected on sales and claim credits for GST paid on purchases.

PAYG withholding

If you employ staff, you’ll need to report the tax you’ve withheld from employee wages.

PAYG instalments

Businesses that expect to owe income tax can pay in instalments through BAS.

Fringe Benefits Tax (FBT) instalments

If you provide fringe benefits (like company cars), you may need to report and pay FBT instalments.

How Often Do You Need to Lodge a BAS?

The frequency of BAS lodgement depends on the size and structure of your business.

Monthly lodgement

Businesses with a GST turnover of $20 million or more must lodge BAS every month. This ensures the ATO receives regular updates on high-volume transactions.

Quarterly lodgement

Most small to medium-sized businesses lodge BAS every quarter. Quarterly lodgement dates are:

• Quarter 1: July – September → Due 28 October

• Quarter 2: October – December → Due 28 February

• Quarter 3: January – March → Due 28 April

• Quarter 4: April – June → Due 28 July

Annual lodgement

Some businesses with minimal GST turnover may qualify for annual BAS lodgement. This option is rare but can ease administrative load.

Methods of Lodging a BAS

There are three main ways to lodge your BAS:

Online via ATO Business Portal

The ATO’s online services let you submit BAS electronically, often with pre-filled fields to save time.

Through a registered tax or BAS agent

Many businesses use an accountant or BAS agent to handle lodgement. Agents also get extended deadlines, which can reduce stress.

Paper form submissions

Although less common today, BAS can still be lodged using paper forms mailed by the ATO.

Deadlines and Penalties for Late BAS Lodgement

Deadlines are strict. Missing them can trigger:

• Failure to lodge (FTL) penalties – These start at $313 and increase with business size and delay length.

• General interest charges (GIC) – Applied daily to unpaid BAS amounts.

• Audit risk – Consistent lateness may flag your business for review.

Using an agent or setting reminders can prevent these unnecessary costs.

Step-by-Step: How to Fill Out a BAS

Filling out a BAS may feel intimidating at first, but breaking it into steps makes it easier.

1. Gather business records

Collect sales invoices, expense receipts, payroll records, and bank statements.

2. Calculate GST on sales and purchases

• Add up GST collected on sales.

• Subtract GST paid on business purchases.

• The difference is either payable or refundable.

3. Report PAYG and other obligations

Include employee tax withholdings, instalments, and any FBT liabilities.

4. Submit and make payment

Lodge via the ATO portal, agent, or mail. Payments can be made through BPAY, direct debit, or credit card.

Common Mistakes to Avoid When Lodging BAS

• Mixing personal and business expenses.

• Forgetting to claim all GST credits.

• Misreporting PAYG withholding amounts.

• Missing deadlines due to poor record-keeping.

Double-checking entries and reconciling accounts regularly helps avoid errors.

Tools and Software That Simplify BAS Reporting

Modern accounting software makes BAS preparation almost effortless. Popular options include:

Xero

Integrates directly with the ATO, enabling quick BAS submissions.

MYOB

Offers built-in GST and PAYG calculators tailored to BAS.

QuickBooks

Tracks GST on sales and purchases in real time, generating BAS-ready reports.

Benefits of Using a BAS Agent

Hiring a BAS agent provides:

• Extended deadlines from the ATO.

• Reduced errors thanks to professional oversight.

• Peace of mind that compliance obligations are met.

For small businesses without dedicated accountants, this support can be invaluable.

Tips to Stay BAS-Ready Year-Round

• Keep receipts and invoices organized.

• Reconcile accounts at least monthly.

• Automate payroll and GST reporting where possible.

• Set calendar reminders for lodgement deadlines.

• Work with your accountant before busy tax periods.

Proactive habits turn BAS from a stressful task into routine business admin.

Frequently Asked Questions (FAQs)

1. What is the due date for BAS?
It depends on your lodgement cycle. Quarterly BAS deadlines are usually 28 days after each quarter, except for December (extended to February).

2. Can I lodge BAS myself?
Yes. You can lodge through the ATO Business Portal, paper forms, or use an accountant/BAS agent.

3. What happens if I don’t lodge BAS?
The ATO may issue fines, charge interest, and increase your risk of audit.

4. Can I get an extension on BAS?
Yes, if you use a registered BAS or tax agent, you may qualify for extended lodgement dates.

5. Do all businesses need to lodge BAS?
No. Only GST-registered businesses (turnover above $75,000) and some with PAYG obligations must lodge.

6. How do I correct a mistake on BAS?
You can revise a lodged BAS using the ATO’s online services or through your tax agent.

Conclusion

The Business Activity Statement (Australia) is more than a tax form — it’s a key part of business compliance and financial management. Staying on top of lodgement deadlines, avoiding common mistakes, and using digital tools or professional support can make the process smoother.

By treating BAS as a regular checkpoint rather than a burden, businesses can keep cash flow healthy and stay in the ATO’s good books.