How to Lodge BAS Online in Australia: Step-by-Step Guide

If the words “BAS is due” make you a little frustrated, you’re not alone.

For most small business owners, lodging a Business Activity Statement (BAS) feels like one more confusing government form on top of an already busy week. The good news? Learning how to lodge BAS online is much simpler than it looks once you understand what is actually required, and there are several easy, ATO-approved ways to do it.

This guide walks you through what a BAS is, who needs to lodge one, and the step-by-step process for each lodgement method, along with common mistakes to avoid.

What Is a BAS?

A Business Activity Statement (BAS) is a form businesses submit to the Australian Taxation Office (ATO) to report and pay their tax obligations.

Depending on your business, this can include:

• GST (Goods and Services Tax) collected and paid
• PAYG (Pay As You Go) withholding – tax withheld from employee wages
• PAYG instalments – prepayments towards your income tax
• Other obligations, such as fuel tax credits or luxury car tax, where applicable

In short, the BAS helps the ATO keep track of what your business owes (or is owed) throughout the year, rather than waiting until your annual tax return.

Who Needs to Lodge a BAS?

You need to lodge a BAS if your business is registered for GST.

This becomes compulsory when your business has an annual turnover of:

• $75,000 or more (most businesses)
• $150,000 or more (non-profit organisations)

Many businesses below these thresholds also choose to register voluntarily.

You’ll also have BAS obligations if you:

• Employ staff and withhold PAYG tax
• Pay PAYG instalments

How Often Do You Need to Lodge?

Your BAS lodgement frequency depends on your business size and GST turnover.

• Monthly: Generally required for businesses with GST turnover of $20 million or more, or those that choose monthly reporting.
• Quarterly: The most common option for small and medium businesses.
• Annually: Available for some businesses voluntarily registered for GST with turnover below $75,000.

The ATO assigns your lodgement cycle when you register for GST, although it can sometimes be changed.

Information You Need Before Lodging

Before lodging your BAS, have the following ready:

• Total sales and income for the period
• GST collected on sales
• GST paid on business purchases and expenses
• Wages paid and PAYG withholding amounts
• PAYG instalment amount (if applicable)
• Bank reconciliation records
• Your ABN and business details

Keeping your bookkeeping up to date can reduce BAS preparation time significantly.

How to Lodge BAS Online: Step-by-Step

There are several ATO-approved ways to lodge your BAS online.

1. Lodge Through ATO Online Services (myGov)

This option is ideal for sole traders with straightforward tax affairs.

Steps:

1. Log in to your myGov account and access the ATO.
2. Go to Business or Tax > Lodgements > Activity Statements.
3. Select the relevant BAS period.
4. Enter your GST, PAYG and income figures.
5. Review your information.
6. Submit your BAS.

Example

Maria runs a mobile hairdressing business in Brisbane. Each quarter she logs into myGov, reviews her income and expenses, enters her GST figures, and usually completes her BAS in under 30 minutes.

2. Lodge Through Online Services for Business

Companies, partnerships and trusts generally use Online Services for Business.

Steps:

1. Sign in using your myGovID.
2. Open Lodgements > Activity Statements.
3. Select the relevant reporting period.
4. Review any pre-filled information.
5. Enter or update your GST, PAYG and other figures.
6. Submit your BAS and note any payment due.

This portal also allows you to:

• View previous BAS statements
• Manage multiple tax obligations
• Arrange payment plans

3. Lodge Through Accounting Software (e.g. Xero)

Many businesses lodge directly through their accounting software.

Steps:

1. Reconcile all bank transactions.
2. Review your GST reconciliation report.
3. Open the Activity Statement section in Xero.
4. Review GST and PAYG figures.
5. Correct any discrepancies.
6. Lodge directly with the ATO.

This method reduces manual data entry and lowers the risk of errors.

Example

David owns a landscaping business. His bookkeeper reconciles the Xero accounts each quarter, checks the GST figures, and David lodges the BAS directly through Xero without entering the information twice.

4. Lodge Through a Registered BAS or Tax Agent

If your BAS is more complex or you’d rather leave it to a professional, a registered BAS or tax agent can lodge it for you.

Typical process:

1. Provide your bookkeeping records or accounting software access.
2. The agent reviews your records.
3. They prepare the BAS.
4. You approve the figures.
5. They lodge the BAS through the ATO agent portal.
6. You receive confirmation and payment details.

Many businesses also benefit from extended lodgement due dates when using a registered agent.

BAS Due Dates in Australia

General BAS due dates are:

• Quarterly: Usually due on the 28th day of the month following the end of the quarter (the December quarter has a later due date).
• Monthly: Due on the 21st of the following month.
• Annual: Due on 31 October.

Registered BAS and tax agents may receive extended due dates.

Common BAS Lodgement Mistakes

Avoid these common errors:

• Recording GST incorrectly
• Failing to reconcile bank accounts before lodging
• Missing invoices or entering duplicate invoices
• Claiming GST credits on private expenses
• Typing incorrect figures
• Lodging after the due date
• Forgetting PAYG withholding amounts

Taking a few extra minutes to review your BAS before submission can prevent unnecessary issues.

What Happens After You Lodge?

After lodgement, the ATO processes your BAS and issues one of the following outcomes:

• Payment required
• Refund payable
• Nil balance

You can view the result through myGov or Online Services for Business.

If payment is required, it is generally due on the same day as your BAS lodgement deadline unless you have arranged a payment plan.

Penalties for Late Lodgement

If you lodge your BAS late, the ATO may apply a Failure to Lodge (FTL) penalty.

Penalties increase every 28 days that the BAS remains overdue, up to the maximum limit. If tax is payable, interest may also be charged.

Repeated late lodgements may attract additional attention from the ATO.

When to Get Professional Help

You should consider working with a BAS or tax professional if:

• Your bookkeeping isn’t fully up to date.
• You’re unsure how GST applies to certain transactions.
• Your business has become more complex.
• You’ve received an ATO review or audit notice.
• You simply want confidence that everything has been lodged correctly.

A registered BAS agent does more than submit the form—they review your records and help identify potential issues before they become problems.

At Clear Tax, we help sole traders and small businesses lodge accurate BAS statements through ATO Online Services, Xero and other accounting software. That means less stress, fewer mistakes and confidence that your BAS has been lodged correctly.

If BAS season is causing you stress, get in touch with Clear Tax. We’ll handle the numbers so you can focus on running your business.

FAQs

How do I lodge BAS online?

You can lodge your BAS through ATO Online Services (via myGov or Online Services for Business), accounting software such as Xero, or through a registered BAS or tax agent.

Can I lodge BAS myself?

Yes. If you’re registered for GST and have accurate financial records, you can lodge your BAS yourself using myGov, Online Services for Business or compatible accounting software.

Can I lodge BAS through Xero?

Yes. Xero allows eligible businesses to review their GST reconciliation and lodge their BAS directly with the ATO once the software is connected.