Quarterly BAS vs monthly BAS at a glance
BAS (Business Activity Statement) is how Australian businesses report and pay GST, PAYG withholding (W), PAYG instalments (I) and other obligations to the ATO.
- Quarterly BAS: lodge and pay four times a year. Lower admin load, suits many SMEs with steady cash flow.
- Monthly BAS: lodge and pay every month. Mandatory for GST turnover of $20m+, common for medium PAYG withholders, and helpful if you want faster GST refunds or monthly numbers.
- If you are not registered for GST but have PAYG instalments/withholding, you may lodge an IAS monthly or quarterly instead of a BAS.
Who must lodge monthly, and who can choose?
- GST turnover $20m+: you must report and pay GST monthly.
- PAYG withholding:
- Small withholder (generally <$25,000 withheld p.a.): usually quarterly via BAS.
- Medium withholder ($25,001–$1m p.a.): monthly via BAS.
- Large withholder (>$1m p.a.): payments are due more frequently; reporting is at least monthly.
- Everyone else: may choose quarterly or monthly. Monthly can be beneficial if you’re often in a refund position (e.g., exporters, capital-intensive or start-up phases).
- Annual GST reporting exists for very small businesses that elect it, but quarterly instalments may still apply—confirm eligibility before choosing.
Unclear which rules apply to you? A BAS agent can check your ATO accounts and confirm your assigned cycle.
Due dates and common concessions
Quarterly BAS
Generally due on the 28th of the month after the quarter ends (Oct, Feb, Apr, Jul). Agent concessions may move these dates—ask your BAS/tax agent for the exact schedule you can rely on.
Monthly BAS
Due on the 21st of the following month. If the 21st falls on a weekend or public holiday, the due date is usually the next business day.
Extensions
Registered agents often receive extended due dates for lodgement. Payment extensions may differ from lodgement extensions. Confirm both to avoid GIC (interest) and penalties.
Practical tip
Set calendar reminders and align bookkeeping cut‑offs so your source data is reconciled at least a week before lodgement.
Pros and cons: quarterly BAS vs monthly BAS
Cash flow impact
Quarterly smooths lodgements; monthly gives faster refunds and earlier visibility of liabilities.
Admin effort & cost
Quarterly means fewer lodgements; monthly spreads the work but requires consistent monthly bookkeeping discipline.
Data quality & visibility
Monthly cycles encourage fresher numbers for management decisions; quarterly can be fine for stable, low‑volume businesses.
Risk & penalties
Monthly reduces the window for errors to compound, but missing monthly deadlines can add up quickly. Quarterly requires strong quarter‑end reviews.
Refund timing
If you are often in a GST refund position, monthly can materially improve cash flow by reducing the wait time.
Complexity
Payroll size and PAYG W status may force monthly. Matching cycles for GST, payroll and management reporting can simplify your finance rhythm.
Fast decision checklist
Choose quarterly BAS if you:
- Have stable cash flow and low-to-moderate transaction volume
- Prefer fewer lodgements per year
- Are a small PAYG withholder and not seeking monthly GST refunds
Choose monthly BAS if you:
- Regularly receive GST refunds or have large input credits
- Want monthly financial visibility for faster decisions
- Are growing quickly or have more complex payroll/PAYG W
- Must report monthly due to ATO thresholds
How to check or change your BAS reporting frequency
- Check your current cycle in ATO Online Services (Business) under Accounts > Activity statements, or ask your agent.
- If eligible, request a change via Online Services or by calling the ATO. Changes generally apply from the start of the next period.
- Align your bookkeeping, payroll and management reporting to the new cycle so cut‑offs and reconciliations are clear.
- Communicate the new timeline to your bookkeeper, accountant and payroll team to avoid missed deadlines.
Need hands-on help? Our BAS agent services and bookkeeping services can implement the cycle and workflow that fits your business.
Frequently asked questions
What is the difference between quarterly BAS vs monthly BAS?
Quarterly BAS lodges and pays once per quarter; monthly BAS lodges and pays each month. Monthly is compulsory for GST turnover of $20m+ and for medium/large PAYG withholders. Others can choose based on cash flow, refund timing and admin preferences.
Which option is usually more cost effective?
Quarterly often costs less in admin time and fees because there are fewer lodgements. However, monthly can be “net cheaper” for refund-heavy businesses because faster GST refunds improve cash flow. Choose based on total impact, not price per lodgement alone.
What are the due dates?
Monthly BAS is due on the 21st of the following month. Quarterly BAS is generally due on the 28th after quarter end (Oct, Feb, Apr, Jul). Agent concessions may change lodgement due dates—confirm your exact calendar with your BAS agent.
Does the best choice change as a business grows?
Yes. Growth, payroll scale and increased transactions often justify monthly reporting. Some businesses start quarterly and move to monthly to get more timely numbers and smoother cash flow.
Can I change frequency mid-year?
Yes, if eligible. You generally change from the start of the next month or quarter, not mid-period. Use ATO Online Services (Business) or ask your BAS/tax agent to request the change.
What if I’m not registered for GST?
You won’t lodge a BAS for GST, but you may still lodge an IAS for PAYG instalments/withholding monthly or quarterly. If you cross the GST registration threshold, review your cycle at the same time.
What should I do before choosing?
Check GST position (refund vs payable), payroll size and PAYG W status, transaction volume, and your need for monthly reporting. If you want help deciding, use the form below to outline your situation.