Understanding GST and BAS Lodgement in Australia: A Guide to Calculation

Managing a business in Australia means more than just serving customers it also means staying compliant with taxes. One area that often confuses business owners is GST and BAS lodgement. What do you need to report? How do you calculate it correctly? And how do you avoid penalties?

In simple terms, GST is the 10% tax you collect on most sales, while BAS is the form you submit to the ATO to report it. Understanding both helps you stay compliant and in control of your cash flow.

Whether you’re a start-up or an established business, this guide will walk you through how GST and BAS work, how to calculate them, and why expert help from a tax accountant makes all the difference.

What is GST (Goods and Services Tax)?

The Goods and Services Tax (GST) is a 10% tax added to most goods and services sold in Australia. The Australian Taxation Office (ATO) says your business must register for GST if it makes $75,000 yearly ($150,000 for non-profits). 

Once registered, you’re required to:

• Charge GST on all taxable sales.
• Collect GST from your customers.
• Get GST credits for things you buy for your business that come with GST. 
• Report and pay the net amount to the ATO through your BAS lodgement.

Example:

You pay the ATO $10 in GST for every $110 you charge for a good. You need to put this amount in your BAS now. 

Who Needs to Register for GST?

Businesses must register for GST if their annual turnover exceeds $75,000. However, even if you earn less, voluntary registration can be beneficial.

Here’s why:

• Input Tax Credits: Once registered, you can get the GST back on purchases you make for your business, which cuts costs. 
• Professional Credibility: GST registration makes your business appear more established and trustworthy to clients.
• Avoid Threshold Stress: If you register voluntarily, you already follow the rules if your income quickly rises above the threshold. 

If you’re unsure whether to register, a tax accountant can assess your business situation and guide you through registration.

What is BAS (Business Activity Statement)?

An ATO Business Activity Statement (BAS) is how a company reports and pays a number of taxes, such as:

• GST collected on sales
• GST credits from purchases
• Pay As You Go (PAYG) withholding and instalments
• Other taxes, such as Fringe Benefits Tax (if applicable)

The BAS allows the ATO to track your business tax activity and determine if you owe a payment or are due for a refund.

Your BAS can be lodged:

• Monthly – For businesses with GST turnover over $20 million.
• Quarterly – The most common option for small and medium businesses.
• Annually – For small businesses under the threshold that choose to lodge once a year.

How to Prepare Your GST and BAS Lodgement

Lodging your BAS correctly starts with knowing how to calculate your GST accurately. Let’s break it down step by step:

1. Calculate GST Collected on Sales

This is the GST you’ve charged your customers on taxable sales.

Example: If you sold goods worth $11,000 (including GST), the GST portion is $11,000 ÷ 11 = $1,000.

2. Calculate GST Paid on Purchases

Costs for business-related purchases or bills include this GST. 

Example: If you purchased supplies for $5,500 (including GST), the GST you can claim back is $5,500 ÷ 11 = $500.

3. Work Out Your Net GST Amount

Subtract the GST paid from the GST collected:

GST Paid = GST on Income – GST Paid on Goods Purchase 

If the result is positive, you owe the ATO. If it’s negative, you’ll receive a refund.

4. Include Other Obligations

The BAS may also include the following items depending on your business:

• PAYG Withholding: Tax withheld from employees’ wages.
• PAYG Instalments: Prepaid income tax for your business.
• Fringe Benefits Tax (FBT): If you give your employees benefits that aren’t cash. 

What Needs to Be Reported in BAS?

When preparing your BAS, you’ll generally need to report:

• GST on Sales: The total GST you collected from customers.
• GST on Purchases: The total GST credits you’re claiming back.
• PAYG Withholding: Amount withheld from employee wages.
• PAYG Instalments: Prepaid income tax based on your business earnings.
• Other Taxes: Such as FBT, if relevant to your business.

If you report your income correctly, your BAS will show what you really did with your money, and you will also avoid penalties from the ATO. 

When to Lodge and Pay BAS

The ATO sets specific due dates for BAS lodgement based on your reporting cycle:

Using a registered tax agent gives businesses more time to file and pay their taxes, one of the many advantages.

Why You Should Work with a Tax Accountant or Tax Agent

Even though you can file your own BAS, many Australian businesses find working with a tax accountant or registered tax agency more convenient.

They help you:

• Prepare and lodge BAS accurately and on time.
• Maximise GST credits and minimise errors.
• Handle ATO correspondence on your behalf.
• Stay compliant with the latest tax regulations.
• Focus on running your business while they manage the numbers.

Tax experts like SMH Accountants & Advisors ensure all the numbers add up and all the due dates are met so that you can relax.

Our qualified accountant in Melbourne specialises in GST and BAS lodgement for small to medium businesses. We take care of calculations, compliance, and reporting so you can focus on what matters most: growing your business.

Contact us immediately to set up a meeting and make your next BAS deposit easy and stress-free.

Pro Tips for Hassle-Free GST and BAS Lodgement

• Keep business and personal finances separate.
• Use accounting software like Xero, QuickBooks, or MYOB.
• Reconcile accounts regularly to stay accurate.
• Save digital copies of tax invoices for at least five years.
• Consult your tax agent before making big business purchases or financial changes.

Proactive record-keeping and expert guidance can save you both time and money.

Conclusion

Finally, every Australian business, whether a new one or one that’s been around for a while, must know how to file GST and BAS. You’ll stay compliant and have a healthy cash flow if you know how to figure out GST, do your BAS properly, and meet deadlines.

Working with a professional tax accountant or agent can seem challenging initially, but it will save you time and money and keep you on the right side of the ATO.