What is a BAS and Who Needs to Lodge One: A Complete Guide for Australian Businesses

Running a business in Australia comes with its fair share of compliance requirements, and one of the most crucial among them is lodging your Business Activity Statement (BAS). Apart from its importance, many small business owners are still not sure about what a BAS actually is or how it works. This confusion often results in late lodgements, errors, and penalties from the Australian Taxation Office (ATO). 

If you’re in this boat, you’re not alone. This comprehensive blog will walk you through everything you need to know about BAS lodgement, including who must lodge one, how to prepare and lodge your BAS, key BAS due dates, and how outsourcing BAS preparation services can save your sanity and your bottom line.

What is a BAS (Business Activity Statement)?

A Business Activity Statement, or BAS, is a form submitted to the Australian Taxation Office that helps businesses report and pay their tax obligations. This includes Goods and Services Tax, Pay As You Go withholding, PAYG instalments, Fringe Benefits Tax (FBT) instalments, Luxury Car Tax (LCT), and Fuel Tax Credits. It’s essentially a snapshot of your business’s financial activity for a specific period and allows the ATO to assess how much tax you owe—or how much of a refund you’re due. If you’re registered for GST, you are legally required to submit a BAS, even if you haven’t made any sales or had any business activity during that period. In that case, you’ll submit what’s called a nil BAS.

The BAS form itself is not overly complex in layout, but the information you put into it must be accurate, timely, and in line with ATO expectations. Errors in reporting GST collected versus GST paid can result in audits, fines, or interest charges. Many business owners make the mistake of rushing through the form at the last minute without reconciling their accounts or cross-checking figures, which leads to avoidable stress and errors.

Who Needs to Lodge Their BAS in Australia?

The moment your business is registered for GST, you’re officially on the ATO’s radar for BAS lodgement. This applies to all business structures—sole traders, partnerships, trusts, and companies. You are required to register for GST if your annual turnover is nearly $75,000 or more, as well as $150,000 or more if you are a non-profit organisation. Once registered, you’ll be issued a BAS form either monthly, quarterly, or annually, depending on your business type and size.

Even if your business doesn’t meet the turnover threshold, some choose to voluntarily register for GST to claim GST credits on business purchases. However, once registered, you're obligated to submit a BAS regularly, even during periods of inactivity. This is often misunderstood by new business owners, leading to penalties for non-lodgement or incorrect reporting.

Think of your BAS like a business tax report card. It tells the ATO what you’ve earned, what you’ve withheld, and what credits or obligations you’re entitled to. This isn’t just paperwork—it’s a legal requirement. Getting it wrong, late, or not at all can cost you far more than just time.

How to Lodge a BAS in Australia: Step-by-Step Process

Lodging your BAS online or through a registered agent involves multiple steps, each requiring attention to detail and thorough record-keeping. Let’s break down the mortgage process... just kidding—it’s just as complicated, but we’ll keep it simple.

1. Collect Financial Records 

The first step you need to undertake when preparing your BAS is to first collect all your financial records that include sales invoices, purchase receipts, bank statements, payroll records and whatever other business expenses or revenue documents you have. It will assist in accurately reporting the GST collected from customers and the GST paid on the purchase of your business goods.

2. Reconcile Your Accounts

Before opening your BAS form, make sure your accounting records match your bank statements. This step is usually skipped; it is very important that it be done correctly. The ATO does not take lightly any discrepancy which can result in under- or over-reporting GST.

3. Complete the BAS Form

Once your numbers are accurate, it’s time to fill out the BAS form. This will include your total sales, GST collected, GST paid, PAYG withheld from employees, and other applicable tax obligations. If you're using cloud accounting software like Xero, MYOB, or QuickBooks, much of this can be automated—but it still needs a human eye to double-check before submission.

4. Lodge the BAS

You can lodge your BAS using:

• The ATO’s online Business Portal
• A registered BAS agent or tax agent
• Some cloud accounting platforms
• Or by posting a paper BAS form (yes, that’s still a thing)

Most businesses prefer to lodge their BAS online for faster processing and instant confirmation of submission.

5. Pay What’s Owed (if anything)

If your BAS shows you owe GST or PAYG, you’ll need to make the payment by the BAS due date to avoid interest charges. The ATO accepts BPAY, credit card, and EFT payments. If you're entitled to a refund, it will be credited to your account.

BAS Due Dates in Australia: Don’t Miss These!

One of the biggest pitfalls in BAS lodgement is missing the deadline. Here’s a breakdown of standard BAS due dates:

If you use a registered BAS agent, you may get extended BAS submission deadlines under the agent concession scheme—another good reason to outsource.

Common BAS Reporting Mistakes to Avoid

Preparing a BAS might sound straightforward, but mistakes are incredibly common, especially for new business owners. Here are some of the most frequent issues:

• Claiming GST on private or ineligible expenses (like meals or personal purchases)
• Forgetting to report PAYG withholding for employee wages
• Misclassifying items (e.g., zero-rated or input-taxed sales)
• Skipping the reconciliation step before lodgement
• Filing late due to poor bookkeeping or missing records
• These aren’t just small errors—they can trigger audits, fines, and a world of ATO follow-up that no business owner wants to deal with.

Why Outsourcing BAS Preparation Services Makes Sense for Australian Businesses?

As your business grows, handling your BAS lodgement in-house can become time-consuming and prone to errors. That’s where outsourcing BAS preparation services can make BAS lodgement an easy process for Australian businesses. Here’s how:

1. Saves Time

Professional BAS providers streamline the entire BAS reporting process. No more late nights reconciling spreadsheets—you hand over the data, and they handle the rest.

2. Accuracy and Compliance

Experts know exactly what the ATO is looking for. They stay up to date with tax law changes and make sure your BAS is submitted error-free every time.

3. Reduces Risk

Avoiding ATO penalties and audits is reason enough to consider outsourcing. Professionals ensure that your reports are complete, accurate, and on time—every time.

4. Gives You Peace of Mind

Running a business is hard enough without tax stress. Outsourcing your BAS preparation allows you to focus on strategy, customers, and growth.

Conclusion: Stay Ahead of BAS, Not Behind It

The Business Activity Statement might be a compliance requirement, but it doesn’t have to be a monthly or quarterly migraine. Understanding what a BAS is, how it’s lodged, and why accuracy matters can save you from costly penalties and ATO attention. If you're unsure about your GST obligations, overwhelmed with deadlines, or just tired of late-night spreadsheets, it might be time to explore professional BAS preparation services.

Don’t wait until the due date creeps up on you. Get your BAS lodgement process streamlined, efficient, and stress-free—whether you do it yourself or let the pros handle it.