Sole Trader BAS Guide

Your business activity statement (BAS) is a quarterly reporting requirement that helps business owners report and pay GST, PAYG instalments and other tax obligations to the Australian Taxation Office (ATO).

Understanding sole trader BAS

A business activity statement is a tax form that sole traders use to report their goods and services tax (GST) and pay as you go (PAYG) instalments, as well as other tax obligations to the ATO. Unlike your individual tax return, which covers the entire financial year, BAS covers shorter reporting periods, typically quarterly.

The biggest difference between BAS and income tax returns is timing and purpose. Your annual tax return calculates your final income tax liability for the year, while a quarterly BAS helps you report and pay taxes throughout the year as your business operates.

When sole traders need to lodge BAS:

• Registered for GST (annual turnover exceeds $75,000).
• Required to pay PAYG instalments.
• Have employees and need PAYG withholding.
• Liable for luxury car tax or wine equalisation tax.

As a sole trader, you will also need these terms::

• Australian Business Number (ABN): Needed for most business transactions.
• GST: 10% tax on goods and services you sell.
• PAYG instalments: Advance payments towards your annual income tax.
• Tax file number (TFN): Used for all tax purposes including BAS.

Why BAS is important for sole traders

Legal compliance is the main reason why sole traders should understand their BAS obligations. Missing lodgement dates or incorrect reporting will result in penalties and interest charges that can significantly affect your business’s cash flow.

Cash flow management through quarterly BAS also helps spread out your tax payments across the year. Instead of being slapped with a massive tax bill annually, you make manageable quarterly payments that line up with your business’s income cycles.

Your business may also be owed a GST refund. You are eligible for GST refunds when your business expenses exceed sales GST. Many sole traders, particularly those in the startup phase or operating seasonal businesses, receive quarterly GST refunds that improve their cash flow.

Late BAS lodgements

Be aware that late BAS lodgement can attract penalties of one penalty unit per period, plus general interest charges on outstanding amounts. Those penalty rates can reach 20% per annum on unpaid amounts.

By being on time, you:

• Avoid penalties and interest charges.
• Better cash flow through quarterly payments.
• Potential GST refunds.
• Maintained good standing with the ATO.
• Simplified annual tax return process.

BAS due dates and lodgment frequency:

Quarterly vs monthly lodgement: Most sole traders lodge their BAS quarterly, but businesses with annual GST turnover exceeding $20 million must lodge monthly.

If you use a registered tax agent, your BAS due dates extend to the 25th of the month following the standard due date.

Note that these due dates apply regardless of whether you have amounts to pay or are claiming refunds. Even ‘nil’ BAS must be lodged by the due date to stay compliant.

Step-by-step guide to lodging your sole trader BAS

To submit your BAS, here are three steps to follow:

Step 1: Know your BAS obligations

Check your GST registration status first. Sole traders must register for GST when their annual turnover reaches $75,000. Once registered for GST, you need to lodge a quarterly BAS regardless of your actual turnover in any specific quarter.

Next, identify your PAYG instalment requirements. The ATO determines if you need to pay PAYG instalments based on your previous tax return. You’ll receive a notification if PAYG instalments apply to your business.

Now it’s time to gather all the necessary business records, including:

• Sales invoices and receipts.
• Business expense receipts.
• Bank statements showing business transactions.
• Previous BAS confirmations (unless it’s your first time).
• Australian Business Number (ABN) details.

Finally, access your BAS through your myGov account linked to the ATO, or wait to receive paper forms by post if you haven’t registered for online services.

Step 2: Calculate GST

To calculate whether you owe the ATO GST or if you are eligible for a GST refund, you first:

1. Calculate GST collected on sales: Add up all GST included in your sales. For GST-inclusive sales, divide by 11 to find the GST component. For GST-exclusive sales, multiply by 10%.
2. Calculate GST paid on business purchases: Total the GST you paid on eligible business expenses.
3. Determine net GST position: If your GST collected on sales exceeds the GST you’ve paid on business purchases, you owe the ATO. If not, then you may be eligible for a refund.
4. Calculate PAYG instalment amount: Use the ATO’s estimated amount or calculate your own variation if your income has changed significantly. Be conservative with variations to avoid interest charges.

Step 3: Lodge and Pay Your BAS

Online lodgement through the Business Portal or myGov means you’ll receive immediate confirmation and faster processing. The system automatically calculates totals and can detect errors before submission.

When it comes time for payment, your options include:

• BPAY using reference numbers provided.
• Credit card through the ATO website.
• Direct bank transfer.
• In-person at Australia Post (for paper forms).

Make sure you pay by the due date to avoid incurring general interest charges. Electronic payments made by 9:30 PM (AEST) on the due date are considered ‘on time’.

Keep confirmation receipts for both lodgement and payment, as these records are important for your business tax obligations and might be requested during ATO reviews.

Common sole trader BAS mistakes

There are some common BAS mistakes to avoid when handling a submission.

Mistake 1: Incorrect calculations

Incorrectly calculating GST on mixed business/personal expenses. Only the business portion of mixed expenses is eligible for GST credits. Keep good records showing business use percentages.

Mistake 2: Failure to lodge nil statements

Failing to lodge a ‘nil’ BAS when no business activity occurred during the quarter. GST-registered businesses must lodge every quarter, regardless of activity levels.

Mistake 3: bad record keeping

Not keeping adequate records for GST claims. The ATO requires substantiation for all GST credits claimed, including tax invoices for purchases over $82.50.

A good practice is to set calendar reminders three weeks before each due date and to use dedicated accounting software. This way, you can automatically track GST on income and expenses, and you won’t be scrambling at the last minute on BAS submissions.

BAS submission example

To put submitting BAS in perspective, let’s look at an example.

Sarah operates a sole trader consulting business, registered for GST with an ABN. Her September quarter results include $15,000 revenue and $3,000 business expenses.

Sarah would calculate her BAS as follows

After she double-checked everything and entered her figures into her accounting software, Sarah lodged her BAS through myGov on October 20th and paid $1,091 before the October 28th due date.

BAS in a nutshell for sole traders

Whether you’re an existing sole trader or just starting out, lodging BAS doesn’t need to be a hassle. To keep ahead of your tax obligations, make sure that you keep your receipts, keep a good track of your sales records and set calendar reminders to avoid late submissions.