BAS Lodging Checklist for Small Businesses
Lodging your Business Activity Statement (BAS) on time is crucial for staying compliant with the ATO and avoiding penalties. This comprehensive checklist will help you prepare and submit your BAS with confidence.
What is a BAS?
A Business Activity Statement (BAS) is a form you submit to the Australian Taxation Office (ATO) to report and pay several tax obligations, including:
- Goods and Services Tax (GST) collected and paid
- Pay As You Go (PAYG) withholding tax (if you have employees)
- PAYG instalment income tax (for some businesses)
Most small businesses lodge BAS quarterly, though some lodge monthly or annually depending on their circumstances.
BAS Due Dates for 2025-2026
If you lodge quarterly online or through a registered tax agent, your BAS due dates are:
- Q1 (July-September):28 October
- Q2 (October-December):28 February
- Q3 (January-March):28 April
- Q4 (April-June):28 August
Late lodgement penalties:
Failing to lodge on time can result in penalties of up to $313 for each period, plus interest charges on unpaid amounts. Mark these dates in your calendar!
Pre-Lodgement Checklist
Before you lodge your BAS, work through this checklist to ensure everything is in order:
- Reconcile all bank transactions
Make sure all income and expenses are recorded in your accounting system and match your bank statements.
- Review all invoices issued
Total up your sales for the quarter (G1 - Total sales including GST). Include all invoices issued, even if not yet paid.
- Verify GST collected
Calculate 1A (GST on sales). If you use GST-inclusive pricing, remember: GST = Total ÷ 11.
- Gather all expense receipts
Collect tax invoices for all business purchases over $82.50. You need these to claim GST credits.
- Calculate GST paid on purchases
Sum up 1B (GST on purchases). Only include business-related expenses with valid tax invoices.
- Check for any adjustments
Include any adjustments from previous periods or corrections from the ATO.
- Verify PAYG withholding
If you have employees, calculate PAYG tax withheld from wages (W1, W2).
- Review previous BAS for errors
Double-check your last BAS to avoid repeating any mistakes.
How to Lodge Your BAS
You have three main options for lodging your BAS:
1. Online through myGov
Link your myGov account to the ATO and lodge directly through the Business Portal. This is the most common method for small businesses.
2. Through a registered tax agent
Your accountant or tax agent can lodge on your behalf. They often have extended due dates.
3. Paper form (less common)
You can mail a paper BAS, but this method has earlier due dates and is slower to process.
Common BAS Mistakes
- Wrong reporting period: Make sure you're reporting for the correct quarter
- GST calculation errors: Double-check your GST amounts (Total ÷ 11 for inclusive prices)
- Missing tax invoices: You can't claim GST credits without valid tax invoices
- Including personal expenses: Only claim GST on genuine business expenses
- Late lodgement: Missing the deadline results in penalties, even if you don't owe anything
Simplify your BAS preparation
BillMate generates BAS-ready reports automatically, so you always know your G1, 1A, and 1B totals.
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