What small business owners need to know about BAS lodgements
Understanding what a BAS is is a key part of staying compliant with the Australian Taxation Office (ATO).
Your Business Activity Statement (BAS) is how you report and pay important business taxes, so knowing how it works can help you avoid surprises and keep your business running smoothly.
🧾 What is a Business Activity Statement (BAS)?
A Business Activity Statement (BAS) is how businesses report and pay certain tax obligations to the Australian Taxation Office (ATO). Most commonly, this includes Goods and Services Tax (GST), but depending on your circumstances it may also include PAYG withholding and PAYG instalments.
Think of the BAS as a summary of your business’s tax activity for a set period — it pulls together what you’ve collected, what you’ve paid, and what needs to be reported to the ATO.
📅 Who needs to lodge a BAS (and how often)?
You’ll generally need to lodge a BAS if your business is registered for GST. Once registered, the ATO will issue BAS forms either:
- Quarterly (most small businesses), or
- Monthly (usually larger businesses or those that choose monthly GST reporting)
Your lodgement frequency is set by the ATO, but in some cases you can request a change.
Even if there’s nothing to report, a BAS still needs to be lodged (this is known as a nil BAS).
📊 Key components of a BAS
While not every BAS will include all sections, these are the most common components small businesses see
💰 GST on sales
This section reports the GST you’ve charged on your taxable sales for the period. It’s important that:
- Sales are correctly coded as taxable, GST‑free or input‑taxed
- GST collected matches what’s been reported in your accounting system
Errors here often come from incorrect GST coding rather than missing income.
🧾 GST on purchases
Here you report the GST you’ve paid on business expenses that are creditable. This is what allows you to claim GST credits.
Common issues in this area include:
- Claiming GST where there is none (e.g. bank fees, wages)
- Claiming GST on private or non‑deductible expenses
- Missing valid tax invoices
PAYG withholding
If you have employees (or make payments subject to withholding), this section reports the tax withheld from wages and other payments.
Amounts reported here should reconcile with:
- Payroll records
- STP reporting
- Amounts actually paid to the ATO
PAYG instalments
PAYG instalments are prepayments towards your expected income tax bill. Not all businesses have this section on their BAS.
Instalments are usually calculated by the ATO based on prior year results, but can be varied if your income changes significantly.
Common small business BAS mistakes
Some of the most common issues I see include:
- Incorrect GST coding in the accounting software
- Mixing private and business transactions
- Reporting cash vs accrual figures inconsistently
- Forgetting to lodge nil BAS
- Not reconciling BAS figures to reports before lodging
These errors often lead to amended BAS, ATO queries, or unexpected tax bills.
How good bookkeeping reduces BAS errors
Accurate, up‑to‑date bookkeeping makes BAS preparation far simpler and far less stressful. When your records are clean:
- GST is calculated correctly
- PAYG amounts reconcile
- BAS figures can be checked quickly against reports
- Lodgements are more confident and defensible
This is where having the right systems — and regular reviews — really pays off.
Final Thoughts
Your BAS isn’t just a form to lodge — it’s a reflection of how well your business records are being maintained behind the scenes. When your systems are set up properly and kept up to date, BAS becomes a routine task rather than a stressful one.
If you’re finding BAS confusing or time‑consuming, it’s usually a sign that something in the process (coding, record keeping, or understanding the requirements) needs tightening up — and that’s something that can be fixed with the right support.
Last updated: May 2026
Disclaimer
The information in this article is general in nature and is not intended to be financial or tax advice. Every business situation is different, so you should consider your own circumstances or seek professional advice before relying on this information.