How To Submit BAS: A Simple Guide For Australian Businesses

Submitting your Business Activity Statement (BAS) is a key responsibility for Australian businesses registered for Goods and Services Tax (GST). Whether you’re a small business owner, a franchisee, or an NDIS service provider, understanding how to complete and lodge your BAS correctly can save you time, avoid penalties, and keep your business compliant with the Australian Taxation Office (ATO).

This comprehensive guide breaks down everything you need to know about bas ato, including what a BAS is, who needs to submit it, how often, and the step-by-step process to lodge your BAS statements. We’ll also cover important details about BAS quarters, due dates, and what to do if you miss a deadline.

What Is BAS? Understanding The Business Activity Statement

The Business Activity Statement (BAS) is a form that businesses use to report and pay several tax obligations to the ATO. This includes GST, Pay As You Go (PAYG) withholding, PAYG instalments, and other taxes such as fringe benefits tax or fuel tax credits, depending on your business.

If your business is registered for GST, you must submit BAS statements regularly. The BAS helps the ATO calculate how much tax your business owes or how much refund you’re entitled to.

Who Needs To Submit BAS?

Any business registered for GST must lodge a BAS. GST registration is mandatory if your annual turnover is $75,000 or more ($150,000 for non-profit organisations). Some businesses may also be required to lodge BAS for PAYG withholding or instalments even if they are not registered for GST.

How Often Do You Need To Submit BAS?

The frequency of BAS lodgement depends on your business turnover:

• Monthly BAS statements: Required if your business has an annual turnover of $20 million or more.
• Quarterly BAS statements: Most businesses with turnover less than $20 million lodge quarterly.
• Annual BAS statements: Available for some small businesses with turnover less than $10 million that have special arrangements.

These reporting periods are often referred to as bas quarters. Understanding your BAS quarters and due dates is essential to avoid late lodgement penalties.

BAS Quarters And Due Dates

If you lodge quarterly, your BAS quarters and due dates are:

BAS Quarter	Reporting Period	Due Date
Quarter 1	July – September	28 October
Quarter 2	October – December	28 February
Quarter 3	January – March	28 April
Quarter 4	April – June	28 July

Note: These due dates apply to the 2025–26 financial year. If using a BAS or tax agent, you may be eligible for extended deadlines.

For monthly BAS lodgers, the BAS is due on the 21st day of the following month. If a due date falls on a weekend or public holiday, the deadline rolls over to the next business day.

Need help tracking your BAS deadlines?

See our full guide to BAS due dates for quarterly, monthly, and annual schedules — plus tips to avoid penalties.

Step-by-Step Guide To Completing Your BAS Statements

Before gathering your financial records, make sure your data is accurate and reconciled. Check that all transactions, expenses, and GST amounts are correctly recorded. This preparation helps ensure your BAS statements are accurate and compliant with the ATO.

1. Gather Your Financial Records

Start by collecting all relevant financial documents for the BAS period, including sales invoices, purchase receipts, payroll records, and bank statements. Accurate records are crucial for completing your BAS correctly.

2. Calculate Your GST Obligations

Determine the total GST collected on your sales and the GST paid on your business purchases. The difference between these amounts is what you will either pay to or claim from the ATO.

3. Complete The BAS Form

Using the ATO’s approved BAS form, fill in the required fields relevant to your business. This may include GST, PAYG withholding, PAYG instalments, and other taxes applicable to your operations.

4. Review And Double-Check

Before submitting, carefully review all figures on your BAS statements. Errors can lead to penalties or delays in processing.

5. Lodge Your BAS And Make Payment

You can lodge your BAS:

• Online via the ATO’s Business Portal or through your accounting software if it integrates with the ATO.
• Through a registered tax or BAS agent.
• By mail if you received a paper BAS form.
• By phone for nil BAS statements.

Once submitted, make any payment due by the BAS due date to avoid interest and penalties.

How To Lodge BAS: Options And Tips

The ATO provides several ways to lodge your BAS statements:

• Online Lodgement: Fast, secure, and often provides extended payment options. Many businesses use accounting software like Xero or MYOB, which integrate directly with the ATO.
• Registered BAS Agent: Using a registered BAS agent like Solve Accounting can reduce errors, ensure accurate reporting, and give you access to extended BAS lodgement deadlines through the ATO.
• Paper Lodgement: If you receive a paper BAS, fill it out carefully and mail it back with payment.
• Nil BAS: If you have no reportable transactions, you can lodge a nil BAS via phone or online.

What Happens If You Miss Your BAS Due Date?

Late BAS lodgement can result in penalties and interest charges. The ATO may impose a Failure to Lodge on Time (FTL) penalty, which increases with repeated late lodgements. If you miss a due date:

• Lodge your BAS as soon as possible.
• Contact the ATO to discuss payment options if you cannot pay the amount owed.
• You may request penalty remission if you have a valid reason for the delay.
• Keep communication open with the ATO to avoid escalation.

Common BAS Mistakes To Avoid

• Incorrect GST calculations: Ensure you correctly separate GST-free sales from taxable sales.
• Missing PAYG withholding amounts: Accurately report amounts withheld from employee wages.
• Filing late or not at all: Always lodge by the due date or request extensions if needed.
• Not reconciling BAS with financial records: Regularly reconcile your BAS statements with your accounting records to avoid discrepancies.

How Solve Accounting Can Help With Your BAS

Navigating BAS lodgement can be complex, especially for franchisees and NDIS service providers. Solve Accounting provides expert support to ensure your BAS statements are accurate, lodged on time, and compliant with ATO requirements.

Our team helps you understand your BAS quarters, prepare your statements, and liaise with the ATO on your behalf.

For tailored assistance, book a call with our team today and take BAS off your to-do list.

FAQs About BAS Submission