How to Lodge Your BAS on Time (And Avoid ATO Penalties)
If you run a small business in Australia, the Business Activity Statement — or BAS — comes around like clockwork. Miss it, and the ATO will notice. Lodge it incorrectly, and you could be paying more than you should. This guide walks you through exactly what you need to know, including due dates, common mistakes, and what to do if you need help.
1. What is a BAS (Business Activity Statement)?
A Business Activity Statement (BAS) is a form you submit to the Australian Taxation Office (ATO) to report and pay several tax obligations at once. Depending on your business, this can include:
- GST (Goods and Services Tax) — the 10% tax collected on most sales
- PAYG Withholding — tax withheld from your employees' wages
- PAYG Instalments — prepayments toward your own income tax
- Fuel Tax Credits — if your business uses fuel in eligible ways
- Fringe Benefits Tax (FBT) instalments
You only need to complete the sections that apply to your business. For many small business owners, BAS is primarily about GST reporting.
2. Who needs to lodge a BAS?
You are required to register for GST — and therefore lodge a BAS — if your business turnover is $75,000 or more per year (or $150,000 for non-profit organisations). If you are voluntarily registered for GST, you'll also need to lodge.
Not sure whether you need to register? The ATO has a clear GST registration guide that walks you through the threshold rules and how to apply.
3. How often do you need to lodge?
The ATO assigns your reporting frequency based on your annual GST turnover. Most small business owners lodge quarterly.
| Turnover | Lodgement Frequency |
|---|---|
| Under $20 million | Quarterly (most small businesses) |
| $20 million or more | Monthly |
| Very low turnover (by election) | Annually |
Standard quarterly BAS due dates (2024–25)
| Quarter | Period | Due Date |
|---|---|---|
| Q1 | 1 July – 30 September | 28 October |
| Q2 | 1 October – 31 December | 28 February |
| Q3 | 1 January – 31 March | 28 April |
| Q4 | 1 April – 30 June | 28 July |
If you lodge through a registered BAS agent, you may be eligible for extended due dates. Check with your bookkeeper or agent — this is one of the most useful benefits of working with a registered professional.
The ATO publishes all key dates in its activity statement lodgement program. It is worth bookmarking or setting calendar reminders each quarter.
4. Step-by-step: How to lodge your BAS
Gather your records
Collect all financial records for the period: sales invoices, purchase receipts, bank statements, and payroll records if you have employees. Good bookkeeping throughout the quarter makes this step quick and painless.
Calculate your GST
Add up GST collected on your sales (1A on the BAS form) and GST credits you can claim on business purchases (1B). The difference is what you owe — or are owed back by — the ATO. The ATO outlines what you can and can't claim as credits.
Report PAYG Withholding (if you have employees)
Report the total amount of tax withheld from wages during the quarter. This should align with your payroll records and your Single Touch Payroll (STP) data, which is sent to the ATO automatically each pay run via your payroll software.
Lodge your BAS
You can lodge via myGov, through your accounting software (Xero, MYOB, QuickBooks), or through a registered BAS agent who can lodge on your behalf and may access extended deadlines.
Pay what you owe by the due date
After lodging, pay any amount owing on time. Options include BPAY, credit card, direct debit (EFT) and Australia Post in person. Full details are on the ATO's payment page.
5. Common BAS mistakes to avoid
Even experienced business owners make these errors. Here is what to watch out for.
5.1 Claiming GST on non-GST items
Not everything has GST on it. Residential rent, basic food and some medical services are GST-free. Claiming credits on these is a common mistake that can trigger an ATO review.
5.2 Missing the lodgement deadline
The ATO charges a Failure to Lodge (FTL) penalty for late BAS. As of 2024–25, this is $330 for every 28 days you are late, up to a maximum of $1,650. It adds up fast. See the ATO's failure to lodge penalty page for current rates.
5.3 Not keeping valid tax invoices
You must hold a valid tax invoice for any purchase where you are claiming a GST credit of $82.50 or more. If records are scattered, now is a good time to get organised — or get help from a bookkeeper.
5.4 Confusing cash and accrual accounting
How you account for GST (on a cash basis vs. when invoices are issued) affects your BAS figures. Make sure your method is consistent and matches what is registered with the ATO.
6. What happens if you can't pay on time?
Life happens. If you cannot pay by the due date, do not ignore it — that is when penalties and interest start stacking up. Contact the ATO proactively to discuss a payment plan. The ATO is generally willing to work with businesses that communicate early.
You can set up a payment plan online via the ATO's online services for business.
7. Don't forget your Fair Work obligations
If your BAS includes payroll, it is worth making sure your employment practices are also in order. The Fair Work Ombudsman is Australia's authority on workplace laws — minimum wages, pay slips, overtime, and leave entitlements.
Getting payroll right goes hand in hand with a clean BAS. A good bookkeeper helps you stay compliant with both the ATO and Fair Work record-keeping requirements at the same time.
8. How RJ Partnering can help with your BAS
If BAS lodgement is eating into your time — or causing stress every quarter — you are not alone. Many Melbourne small business owners find that outsourcing their bookkeeping and BAS to a professional pays for itself in time saved and peace of mind.
At RJ Partnering, we handle BAS lodgements for small businesses across Melbourne, whether it is a one-off catch-up or as part of an ongoing bookkeeping package. As a Tax Practitioners Board (TPB) registered BAS agent, we can also lodge on your behalf and access extended due dates.
We explain everything in plain language — no accounting jargon, no surprises. Just clear, reliable BAS support for Melbourne small businesses.
Frequently asked questions about BAS lodgement
This article is general in nature and does not constitute financial or tax advice. For advice specific to your business, please consult a registered tax professional or contact the ATO directly.