The Business Activity Statement (BAS) is the single most important tax form for any Australian retail shop owner.
It is where you report GST collected from customers, GST paid on business purchases, PAYG withholding, and other tax obligations.
New business owners often feel overwhelmed by BAS — but once you understand the structure, it becomes routine.
This guide explains who needs to lodge BAS, how to calculate each label, common errors, and deadlines.
1. Who Must Lodge a BAS?
You must lodge a BAS if any of the following apply:
- You are registered for GST (mandatory or voluntarily).
- You have PAYG withholding obligations (you employ staff).
- You have PAYG instalments (ATO asks you to pay tax in advance).
- You have other obligations like Luxury Car Tax (LCT) or Wine Equalisation Tax (WET).
If you are a sole trader with no employees and not registered for GST, you generally do NOT lodge a BAS. Instead, you report business income in your individual tax return.
2. BAS Reporting Cycles (How Often You Lodge)
When you register for GST, the ATO assigns you a reporting cycle based on your turnover:
- Quarterly (most common for retail shops): Turnover under $20 million. Due dates: 28 October (Jul-Sep), 28 February (Oct-Dec), 28 April (Jan-Mar), 28 July (Apr-Jun).
- Monthly: Optional for businesses with turnover under $20 million (or mandatory if you voluntarily choose it). Due 21st of following month.
- Annually: Only for businesses with GST turnover under $75,000 that voluntarily registered.
If your due date falls on a weekend or public holiday, the due date is the next business day.
3. Key BAS Labels Explained (For Retail Shops)
Your BAS will have multiple labels. Here are the ones most relevant to a shop owner:
- G1 (Total sales): All your sales including GST (cash, card, online, lay-by deposits).
- G2 (Export sales): If you ship goods overseas (GST-free).
- G3 (Other GST-free sales): For example, selling basic food items, medical supplies, or education.
- G10 (Capital purchases): Assets like a shop fridge, shelving, or a vehicle (GST included).
- G11 (Non-capital purchases): Normal trading stock, rent, electricity, cleaning, advertising (GST included).
- 1A (GST owed to ATO): Calculated as (G1 - G2 - G3) ÷ 11.
- 1B (GST refund from ATO): (G10 + G11) ÷ 11.
- W1 (PAYG withholding): Total tax withheld from employees during the period.
- W2 (PAYG instalment): If ATO asks you to pre-pay income tax.
Example: If your total sales (G1) = $110,000 (including $10,000 GST), and your total purchases (G10+G11) = $55,000 (including $5,000 GST), then you owe the ATO $10,000 - $5,000 = $5,000. This goes into label 1A.
4. How to Complete Your BAS (Step by Step)
You have two options:
Option A — Accounting software (recommended): Xero, MYOB, QuickBooks, or Reckon can automatically generate BAS figures from your transactions.
You review, confirm, and lodge electronically via the software or ATO portal.
Option B — Manual calculation: Use a spreadsheet or paper BAS form. You'll need:
Total sales figures (from your POS system or bank deposits).
Total GST on purchases (from tax invoices — you must keep them).
PAYG withholding total (from your STP reports).
Then log into the ATO Business Portal and enter numbers manually.
5. Common BAS Mistakes (Costly Errors to Avoid)
- Claiming GST on private purchases: You cannot claim GST on your morning coffee or personal groceries just because you bought them on the shop's bank card.
- Forgetting to report cash sales: All cash payments into the till are taxable sales — the ATO uses industry benchmarks to estimate cash income.
- Mixing up G10 and G11: Assets over $300 (e.g., a new EFTPOS terminal) go in G10, while consumables (light bulbs, cleaning spray) go in G11.
- Lodging late: The ATO charges a failure-to-lodge penalty starting at $222 for small entities, increasing for each 28 days overdue (up to $1,110). Plus General Interest Charge.
6. What If You Can't Pay the GST Owed?
If your BAS shows you owe the ATO money but your shop has cashflow problems, do NOT simply not lodge.
Instead:
- Lodge on time (even if you can't pay) — avoiding the late lodgment penalty.
- Contact the ATO immediately via phone or your tax agent to request a payment plan (deferred payment arrangement).
- If you owe less than $100,000, you can set up an automated payment plan online (up to 24 months).
Critical: Ignoring a BAS debt leads to garnishee notices (ATO takes money directly from your shop's bank account) and potential director penalties.
In summary, BAS is manageable if you keep good records. Use cloud accounting software, reconcile weekly, and lodge on time.
If BAS feels overwhelming, hire a registered BAS agent for a few hundred dollars per quarter — their cost is tax-deductible.