What Is BAS and Do I Need to Lodge It?

A Business Activity Statement – BAS – is the form Australian businesses use to report and pay GST, PAYG withholding and other tax obligations to the ATO. If your business is registered for GST, you are required to lodge one. Most small businesses lodge quarterly, though some lodge monthly or annually depending on their turnover and circumstances.

This guide covers what goes into a BAS, who needs to lodge one, when it is due, what happens if you miss the deadline, and what it costs to have someone lodge it for you.

What Does a BAS Actually Include?

A BAS is not just a GST form. Depending on your business situation, it can include several different obligations rolled into a single lodgement.

GST

This is the main component for most small businesses. You report the total GST you collected on sales during the period, subtract the GST you paid on business purchases (your input tax credits), and either pay the difference to the ATO or receive a refund if your credits exceed your collections. If your business is not registered for GST, this section does not apply to you.

PAYG withholding

If you have employees, you are required to withhold tax from their wages and send it to the ATO. PAYG withholding is reported on your BAS each quarter and paid at the same time. This is separate from super – super is paid directly to each employee’s fund and is not reported on the BAS.

PAYG instalments

If you earn business or investment income that is not subject to withholding – for example, sole trader income or income from a trust – the ATO may require you to pay tax in advance through PAYG instalments. This is to avoid a large tax bill at the end of the year. Not every business will have this on their BAS, but it appears once your income reaches a certain threshold.

Other obligations

Depending on your business structure and circumstances, your BAS may also include FBT instalments (Fringe Benefits Tax) and fuel tax credits. These are less common for most small businesses but are part of the same lodgement process if they apply.

Who Needs to Lodge a BAS?

You need to lodge a BAS if your business is registered for GST. GST registration is mandatory once your annual turnover reaches $75,000 – or $150,000 for non-profit organisations. The $75,000 threshold applies to any rolling 12-month period, not just the financial year, so you need to monitor your turnover throughout the year rather than checking once at 30 June.

There is one important exception. Taxi, limousine and rideshare drivers must register for GST from the first dollar earned regardless of turnover. If you drive for Uber, DiDi or a similar platform, you are required to be registered for GST and lodge BAS from day one.

If your turnover is under $75,000 and you have not voluntarily registered for GST, you do not need to lodge a BAS. You may still need to lodge other activity statements if you have PAYG withholding obligations from having employees, but that is handled separately.

Quick tip: If you are approaching $75,000 in turnover, register for GST before you cross the threshold rather than after. Once you exceed it, you have 21 days to register and your GST obligations technically begin from when you crossed the threshold – meaning you may owe GST on sales made before you registered.

How Often Do You Need to Lodge a BAS?

Most small businesses lodge quarterly. The ATO assigns your lodgement frequency based on your GST turnover, though you can request to change it in some circumstances.

Quarterly (most common)

Businesses with GST turnover under $20 million typically lodge quarterly. Each quarter covers a three-month period and the BAS is due the following month. The quarterly due dates for 2025-26 are:

Note that Q2 (the December quarter) has no agent extension – it is due 28 February regardless of who lodges it. AffordBooksTax clients get the extended agent deadlines on all other quarters as standard.

Monthly

Businesses with GST turnover of $20 million or more are required to lodge monthly. Some smaller businesses also choose to lodge monthly voluntarily – usually because they are regularly in a GST refund position and want their credits back faster. Monthly BAS is due on the 21st of the following month with no extensions.

Annually

Businesses with a very low GST turnover (generally under $75,000 who have voluntarily registered for GST) can sometimes arrange annual lodgement. Annual BAS is due on 31 October. This is less common and not available to all businesses.

What Happens If You Miss the BAS Deadline?

Missing a BAS deadline has two consequences – a fixed penalty for late lodgement and interest on any amount unpaid.

The Failure to Lodge (FTL) penalty for small businesses (turnover under $1 million) is $364 per 28-day period overdue. If you are four weeks late, that is $364. Eight weeks late, that is $728. The penalty is capped at five units ($1,820) but compounds quickly. For medium businesses (turnover $1 million to $20 million) the penalty doubles to $728 per period.

On top of the FTL penalty, the ATO charges the General Interest Charge (GIC) on any tax you owe. The GIC rate for the July to September 2026 quarter is 11.43% per annum, compounding daily. This used to be tax-deductible but from 1 July 2025 it is no longer deductible – meaning the real cost of late payment is now higher than it used to be.

The ATO can also place you in a higher risk category if you have a history of late lodgements, which can trigger reviews or audits. Getting back on track – and staying there – is always cheaper than managing the consequences of falling behind.

If you have missed past BAS lodgements and need to catch up, our catch-up bookkeeping service can get your records in order so we can lodge outstanding BAS correctly and minimise penalties where possible.

What Is the Difference Between a Nil BAS and a Regular BAS?

If your business had no income and no expenses during a BAS period, you still need to lodge. This is called a nil BAS. You are not excused from lodging just because there was no activity – the obligation exists as long as you are registered for GST.

Lodging a nil BAS is straightforward – all amounts are zero and it takes a few minutes. But failing to lodge a nil BAS attracts the same FTL penalty as failing to lodge a regular one. If your business is temporarily inactive, it is worth considering whether to cancel your GST registration to remove the lodgement obligation while you are not trading.

How Much Does BAS Lodgement Cost?

If you lodge your own BAS through the ATO’s Online services for business or your accounting software, there is no charge. The cost comes from the time involved – reconciling your accounts, checking your GST figures, and completing the lodgement correctly.

Having a registered BAS agent prepare and lodge your BAS removes that burden and reduces the risk of errors. At AffordBooksTax, BAS lodgement is priced by revenue tier with no hidden fees:

All prices exclude GST. See the full pricing page for the complete breakdown including bookkeeping and payroll.

Can You Lodge BAS Yourself or Do You Need an Agent?

You can lodge your own BAS through the ATO’s Online Services for Business or through your accounting software if it is connected to the ATO. Xero, which all AffordBooksTax clients use, allows direct BAS lodgement from within the software once it is connected to your ATO account.

The main reasons to use a registered BAS agent are accuracy, time saving, and the extended lodgement deadline. A BAS agent can only lodge on your behalf if they are registered with the Tax Practitioners Board (TPB). Always check a bookkeeper’s TPB registration before letting them prepare or lodge your BAS – unregistered individuals are not legally permitted to provide BAS services for a fee.

AffordBooksTax is a registered tax agent, which means we can both prepare and lodge your BAS and you benefit from the extended agent deadline on most quarters. For businesses in Melbourne, Sydney and across Australia, everything is handled remotely through Xero – there is no need to come into an office.

Frequently Asked Questions

What does BAS stand for?

BAS stands for Business Activity Statement. It is the form Australian businesses registered for GST use to report and pay their tax obligations to the ATO, including GST, PAYG withholding and PAYG instalments. Most small businesses lodge quarterly.

Do I need to lodge a BAS if my business made no money?

Yes. If you are registered for GST, you must lodge a BAS every period regardless of whether you had any income or expenses. A BAS with all zero amounts is called a nil BAS and must still be lodged by the due date to avoid a Failure to Lodge penalty.

What happens if I lodge my BAS late?

The ATO automatically issues a Failure to Lodge penalty of $364 per 28-day period for small businesses with turnover under $1 million. Interest also accrues daily on any unpaid tax at the current GIC rate of 11.43% per annum. From 1 July 2025, this interest is no longer tax-deductible. Lodging late – even without an amount owing – still attracts the penalty.

How do I know how much GST to pay on my BAS?

Your GST liability is the difference between the GST you collected on sales and the GST you paid on business purchases (your input tax credits). If you reconcile your accounts properly in Xero throughout the quarter, Xero calculates this automatically and pre-fills your BAS figures. This is one of the main reasons AffordBooksTax onboards all clients to Xero – it makes BAS preparation significantly faster and more accurate.

Can my bookkeeper lodge my BAS for me?

Only if they are a registered BAS agent with the Tax Practitioners Board. Providing BAS services for a fee without TPB registration is illegal in Australia. Always ask to see your bookkeeper’s TPB registration before letting them prepare or lodge your BAS. You can search the TPB register at tpb.gov.au to verify anyone’s registration status.

What is the difference between BAS and tax return?

A BAS reports your ongoing tax obligations during the year – mainly GST and PAYG – and is lodged quarterly or monthly. A tax return is an annual lodgement that calculates your total income tax liability for the financial year, taking into account all income and deductions. They are separate obligations. If you need help with both, our tax return service and BAS lodgement checklist cover each one in detail.