In 2025, lodging your Business Activity Statement (BAS) online is not only the most efficient option, it’s also the standard approach expected by the Australian Taxation Office (ATO). For most GST-registered businesses, electronic lodgement offers a faster, more secure process, often accompanied by an extended deadline for payment.
Whether you’re a sole trader lodging directly through the ATO portal or a business using cloud-based software, this guide walks you through the process clearly and confidently, with no unnecessary jargon.
What Is a BAS and Who Needs to Lodge One?
A Business Activity Statement (BAS) is the ATO’s mechanism for businesses to report and pay tax obligations such as Goods and Services Tax (GST), Pay As You Go (PAYG) withholding, PAYG installments, and, in some cases, other taxes like fuel tax credits, luxury car tax, or wine equalisation tax.
If your business is registered for GST or required to withhold tax from employee wages, you must lodge a BAS periodically. The frequency of lodgement, monthly, quarterly, or annually, depends on your business size and ATO registration details.
Example: Sarah owns a Melbourne-based online store with $150,000 in annual turnover. She’s registered for GST and pays staff, which means she must lodge a quarterly BAS covering GST collected, PAYG withheld, and her PAYG installment.
Accurate and timely BAS lodgement is not just about compliance; it’s about maintaining financial control, planning cash flow effectively, and avoiding avoidable ATO penalties. If your business needs structured support around BAS cycles and due dates, our tax compliance services provide clarity across all lodgement types.
How to Lodge a BAS via the ATO Business Portal
Lodging your BAS directly through the ATO’s Online Services for Business is a secure, paperless way to meet your reporting obligations while maintaining full control over your business tax data.
What You’ll Need
Before you begin, ensure the following are in place:
- A valid myGovID, linked to your ABN via the ATO’s Relationship Authorisation Manager (RAM)
- Access to the ATO Online Services for Business portal
- A reconciliation of your financial data for the reporting period
This method is best suited for businesses comfortable entering data manually and managing their own tax reporting without third-party software or agent support.
Step-by-Step Lodgement Process
- Log in to the ATO’s Online Services for Business using your myGovID.
- Navigate to ‘Lodgments’ → ‘Activity Statements’.
- Select the BAS period you wish to lodge.
- Fill out relevant sections:
- GST collected and GST credits
- PAYG withholding (if you have employees)
- PAYG installments (if applicable)
- Other obligations, such as LCT, WET, or FTC
- Carefully review your figures against your accounting records.
- Click ‘Submit’ to lodge electronically.
- Save or record the lodgement receipt number as proof.
Tip: Lodging through the ATO portal typically gives you an extra two weeks to lodge and pay compared to paper forms, especially if you lodge quarterly.
The ATO’s portal is reliable, but requires diligence in data entry. If your records are not up-to-date or reconciled, errors can quickly lead to FTL penalties or interest charges.
How to Lodge a BAS via Accounting Software
For businesses using cloud platforms like Xero, MYOB, QuickBooks, or Reckon, BAS lodgement can be fully integrated into your accounting workflow. These systems are Standard Business Reporting (SBR)-enabled, which means they securely connect to the ATO for direct submission.
This option is ideal for businesses with multiple transactions, payroll obligations, or those wanting to reduce manual data entry errors.
Lodgement Steps in Software
- Confirm your software is linked to your ABN and connected to the ATO.
- Reconcile all transactions in your accounting file for the relevant BAS period.
- Generate the BAS report within your software dashboard.
- Review pre-filled figures for:
- GST collected and credits
- PAYG withholding
- PAYG instalments
- Select ‘Lodge with ATO’ or equivalent in your platform.
- Confirm submission.
- Save or download the BAS lodgement receipt.
Benefit: Software-based BAS lodgement reduces risk by pulling figures directly from your accounts, ensuring consistency between your bookkeeping and ATO reporting.
Using platforms like Xero also enables real-time compliance tracking and integrates seamlessly with payroll and Single Touch Payroll (STP) systems. For many small and medium businesses, this method simplifies the entire reporting cycle, particularly when supported by a Virtual CFO or internal accountant.
Paying or Receiving Your BAS Outcome
Once your BAS has been lodged, the ATO will determine whether your business owes a payment or is entitled to a refund.
If You Owe the ATO
You can make your BAS payment using any of the following methods:
- BPAY (using the reference on your activity statement)
- Direct credit via internet banking
- Credit card via the ATO’s payment portal
- Payment plan through the ATO Online Services for Business (if cash flow is tight)
If your business is facing difficulty meeting BAS obligations on time, it’s essential to act early. The ATO may allow structured payment arrangements, but penalties and interest can still apply if you delay action. Learn more about how Blackwattle Tax supports clients with ATO payment plans tailored to their cash flow position.
If You’re Owed a Refund
If your BAS results in a credit, for example, if your GST credits exceed GST collected, the ATO will deposit the refund into your nominated business bank account, usually within a few days of lodgement.
Example: Michael operates a transport business and recently purchased several capital assets. His GST credits exceed what he collected from customers. Upon lodging his BAS through MYOB, he receives a refund into his business account five days later.
BAS Lodgement Due Dates for 2025
Staying ahead of BAS due dates is critical to avoiding late lodgement penalties and interest charges.
Quarter | Reporting Period | BAS Due Date |
Q1 | 1 July – 30 September 2025 | 28 October 2025 |
Q2 | 1 October – 31 December 2025 | 28 February 2026 |
Q3 | 1 January – 31 March 2026 | 28 April 2026 |
Q4 | 1 April – 30 June 2026 | 28 July 2026 |
For monthly lodgers, the due date is typically the 21st of the following month.
Note: If you use a registered tax or BAS agent, such as Blackwattle Tax, you may be eligible for extended lodgement deadlines under the ATO’s agent concessional program.
Lodging on time is more than a formality; it protects your business from Failure to Lodge (FTL) penalties, which increase the longer your BAS remains overdue. These penalties are calculated based on the size of your business under the ATO’s penalty unit system, currently governed by the Taxation Administration Act 1953 – Schedule 1, Section 286-75.
What Happens If You Lodge Late or Make a Mistake?
Late or incorrect BAS lodgement can have compounding consequences.
Penalties for Late Lodgement
If you miss your BAS due date, the ATO may apply an FTL penalty, increasing every 28 days until it’s lodged (capped at five units). The penalty amount is based on your business size:
- 1 penalty unit for small businesses
- 2–5 units for medium or large withholders or larger entities
Interest may also be charged on unpaid GST or PAYG amounts, calculated as General Interest Charge (GIC).
Amending an Incorrect BAS
Mistakes can happen, but they can be corrected, ideally, before the ATO initiates any compliance action. You can revise a BAS through:
- The ATO Business Portal
- Your accounting software (if supported)
- A registered tax or BAS agent
Scenario: A design agency underreported GST collected due to incorrect invoice coding in Xero. After reconciling the issue, they revised the BAS in their next quarter’s lodgement and avoided further ATO review.
When errors are frequent or complex, professional review is highly recommended to prevent exposure to audits. Blackwattle Tax assists clients with BAS amendments, reconciliations, and ATO correspondence where required.
Practical Tips to Simplify BAS Lodgement
Efficiency in BAS preparation comes down to one key principle: maintain clean, current records throughout the reporting period.
Here’s how to make BAS lodgement less stressful:
- Reconcile bank accounts monthly, not just at BAS time
- Use cloud-based software (Xero, MYOB, etc.) to automate GST tracking
- Keep digital copies of invoices with GST breakdowns
- Set ATO calendar reminders or automate through your software
- Work with a registered BAS agent for reviews or complex scenarios
- Store records securely for at least five years, as required under Division 900 of ITAA 1997
For growing businesses juggling multiple obligations, pairing BAS lodgement with Virtual CFO services can streamline reporting and ensure compliance is never an afterthought.
Should You Lodge via the ATO Portal, Software, or a BAS Agent?
Each lodgement method has its benefits; the right option depends on the size and complexity of your business, as well as your confidence with reporting obligations.
Method | Best For | Pros | Considerations |
ATO Portal | Sole traders or micro-businesses | Free, direct lodgement, extra time to pay | Manual entry required, more prone to error |
Accounting Software | Small to medium businesses using Xero, MYOB, etc. | Automated data, time-saving, integrated with STP | Requires setup and regular reconciliation |
BAS Agent | Complex structures or growing businesses | Expert oversight, ATO-compliant, extensions | Service fees apply, but are often offset by savings |
Example: A cafe with a single employee may be fine using the ATO portal. However, a medical practice operating through a discretionary trust with multiple staff, STP, and R&D reporting obligations will benefit from a registered BAS agent ensuring all tax positions are accurate and strategic.
At Blackwattle Tax, we support businesses across all sectors, from trades to transport and e-commerce, by integrating BAS lodgement into a broader compliance and forecasting strategy.
Final Word
BAS lodgement is a recurring, non-negotiable part of doing business in Australia, but it doesn’t need to feel like a burden. Whether you lodge through the ATO’s Online Services for Business or use SBR-enabled software, what matters most is that your records are accurate, your submissions are timely, and your reporting method suits your operations.
For businesses looking to move beyond compliance and into financial clarity, combining automated systems with expert advice ensures every BAS is an opportunity, not a liability.
Ready to lodge with confidence?
Book a free 30-minute consultation with a Chartered Accountant at Blackwattle Tax. We’ll review your lodgement method, identify any compliance gaps, and help you reduce the risk of ATO penalties, without the overwhelm.
Disclaimer: This article provides general information only and does not constitute legal or tax advice. You should consult a registered tax agent for advice relevant to your specific circumstances.
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Disclaimer: We endeavour to make sure the information provided in this guidance is up to date and accurate. Please note, that the information is only intended to be a guide, with a general overview of information. This guidance is not a comprehensive document and should not be interpreted as legal advice or tax advice. The information is general in nature. You should seek the assistance of a professional opinion for any legal and tax issues related to your personal circumstances.