Introduction
In Australia, "quarterly business tax filing" usually means lodging a Business Activity Statement (BAS). It is not a quarterly income tax return. Your income tax return is still annual.
That distinction trips up plenty of owners. Common problems include missing an ATO deadline, mixing up GST with income tax, underestimating PAYG obligations, or lodging figures that don't match the books.
This guide covers who must lodge, what a quarterly BAS includes, how to prepare it, current ATO due dates, payment steps, and when to bring in professional help. Always confirm figures against the ATO before you lodge.
Key Takeaways
- Your quarterly obligations depend on your registrations, structure, employees and ATO reporting cycle.
- A BAS is separate from PAYG instalments, PAYG withholding and the annual income tax return.
- Reconcile your books and review GST, payroll and instalment figures before lodging.
- Check current ATO due dates, payment instructions and correction rules each period.
What Does Quarterly Business Tax Filing Mean in Australia?
What a quarterly BAS is
A BAS is the statement a GST-registered business uses to report and pay GST, PAYG instalments, PAYG withholding and other applicable taxes. What appears on yours depends on your registrations. Two businesses rarely lodge identical forms.
A nil BAS may still be required when you had no activity in the period.
Quarterly BAS versus an annual income tax return
A BAS reports periodic obligations such as GST and selected PAYG amounts. The annual return reports taxable income for the financial year, and it is required even if there was no income. The return type depends on your structure.
Lodging a BAS never replaces the annual return, financial statements or other compliance filings. PAYG instalments paid through your BAS are credited when the annual return is assessed.
The difference between lodging and paying
Lodging and paying are separate obligations. You can lodge on time and still owe a payment, or the reverse. If you are struggling to pay, contact the ATO before the due date.
BPAY and ATO online services are the preferred payment options. Use the correct payment reference number. Other methods include direct credit, Government EasyPay and Australia Post. Credit-card payments to the ATO cease after 30 June 2027.
Who Must Lodge a Quarterly BAS and What Does It Include?
Businesses with GST obligations
GST-registered businesses lodge a BAS. You must register when your GST turnover reaches $75,000 ($150,000 for non-profits). Taxi and ride-sourcing drivers must register regardless of turnover.
Register within 21 days of becoming required. Apply rolling 12-month tests for current and projected turnover.
Businesses with GST turnover of $20 million or more report monthly. Entity type alone doesn't decide your reporting frequency, but it does change who pays the tax:
| Structure | Annual income tax reporting |
|---|---|
| Sole trader | Business income goes in the individual's return |
| Partnership | Partnership return; partners generally pay tax on their shares |
| Company | Company return; company pays its own tax |
| Trust | Trustee lodges; beneficiaries generally taxed |
PAYG instalments
PAYG instalments are prepayments toward your annual income tax. The ATO usually enters you into the system after an assessed return and notifies you electronically or by letter. You can also opt in voluntarily.
These instalments are not GST. The amount is either an ATO-calculated figure or your instalment income multiplied by an instalment rate.
PAYG withholding and employees
You withhold tax from employee payments and certain contractor payments, including payments where no ABN is quoted. Single Touch Payroll (STP) reports employee payments each payday, but it does not remit the withholding. Small withholders report and pay quarterly; medium withholders monthly.
Withholding is the employees' tax, not your own. Keep payroll reports, income statement data and withholding records to support the figures.
Other obligations that are not part of a BAS
- Super guarantee: 12% in 2026-27. From 1 July 2026, contributions generally must reach the fund within 7 business days of payday.
- Payroll tax: a state or territory tax. Revenue NSW, for example, uses separate monthly and annual returns.
- Fringe benefits tax: a separate annual return for the 1 April to 31 March FBT year.
Cross-border dealings
- Most imports attract GST before release, though deferral arrangements exist.
- Exports are GST-free if exported within 60 days of invoice or payment, subject to conditions.
- Offshore purchases may trigger reverse-charge rules. Give suppliers your ABN and GST status.
How to Prepare and Calculate Quarterly Business Tax Obligations
Start with reconciled records
Before opening the BAS, reconcile bank accounts, sales, purchases, invoices, expenses and payroll against your accounting software. Keep private and business transactions separate. Check that every transaction carries the right GST code.
Keep records for 5 years from when they were prepared or the transaction was completed, whichever is later.
Calculate GST correctly
GST payable is GST collected on taxable sales minus GST credits on eligible business purchases. A positive result is payable; a negative one is a refund.
- Hold a tax invoice for purchases over $82.50 including GST before claiming the credit.
- Invoices of $1,000 or more must also identify the buyer or their ABN.
- Apportion private use. Claim only the business portion.
- GST-free and input-taxed sales both exclude GST on the sale. Credits are generally available for GST-free sales, but not input-taxed ones.
- Cash accounting counts GST as payments are made or received. Non-cash accounting generally uses the earlier of invoice or payment.
Common labels: G1 total sales, 1A GST on sales, 1B GST on purchases. Full reporting adds G2, G3, G10 and G11.
Estimate PAYG instalments
Review current income, the ATO's prior information, expected revenue changes and deductible expenses. You can vary instalments by the due date and before lodging your annual return. Underestimating can attract general interest charge (GIC).
Illustrative example only, not tax advice: a business expects steady income but wins a large contract in quarter three. Its instalments no longer reflect the real income. Reviewing and varying the later instalments avoids a large shortfall at annual assessment.
Check PAYG withholding
Compare payroll records with the W1 to W5 labels. If you report through STP, check prefilled amounts. Contractor payments and employee classifications can be complex, so review them separately.
Pre-lodgement checklist
- Confirm the correct reporting period.
- Re-check GST calculations and prior-period adjustments.
- Match PAYG figures to payroll and ATO notices.
- Gather supporting documents.
- Confirm the authorised lodger and payment amount.
- Explain any large movement from last quarter and note why.
- Save the confirmation record.
Quarterly Deadlines, Lodgement, and Payment
Find the right due date
The standard quarterly ATO due dates apply to both the 2026-27 and 2027-28 years:
| Quarter | Standard due date | 2026-27 agent concession |
|---|---|---|
| July to September | 28 October | 25 November 2026 |
| October to December | 28 February | None |
| January to March | 28 April | 26 May 2027 |
| April to June | 28 July | 25 August 2027 (provisional) |
Weekend and public-holiday deadlines move to the next business day. Eligible online quarterly lodgers get an extra two weeks, except for the December quarter. Agent concessions have conditions. Confirm your own dates with the ATO, not an old calendar.
Choose a lodgement method
- Online services for business (replaces the old Business Portal)
- myGov, for eligible sole traders
- SBR-enabled accounting software
- A registered tax or BAS agent (check the TPB Register)
After you lodge, keep the submitted figures, payment receipt, confirmation number and reconciliations.
Arrange payment and manage cash flow
GST collected isn't your money. Set funds aside through the quarter and check cash flow before the deadline. Avoid a fixed savings percentage unless a current professional calculation supports it.
Extensions and missed deadlines
Deferrals exist for qualifying exceptional circumstances. Don't assume a deferral also delays payment; only some approved agent deferrals do.
If you miss a deadline, lodge or pay as soon as possible and contact the ATO or your agent.
The failure to lodge penalty for a small entity is 1 penalty unit per 28 days or part, up to 5 units, at $364 per unit from 1 July 2026. GIC for October to December 2026 is 11.51% annually, compounding daily.
You can request remission of penalties and interest, and ask for a payment plan.
Prepare for the next quarter
Diarise the next deadline, schedule bookkeeping reviews and set an internal document cut-off ahead of the ATO date. Quarterly reviews reveal falling margins, payroll errors and cash pressure earlier.
Common Mistakes and When to Seek Professional Help
Frequent errors the ATO sees:
- Lodging with unreconciled accounts
- Claiming credits on purchases that had no GST
- Claiming credits without holding the required tax invoice
- Duplicate invoices or omitted sales
- Wrong cash-accounting period
- Confusing GST with PAYG instalments
An error is something that was incorrect when first reported. An adjustment reflects a later change in circumstances. Eligible errors can be fixed on a later BAS; otherwise you revise the original.
The ATO's example: a $15,000 debit error in a garage business exceeded the later-BAS limit, so the original BAS had to be revised. GST credit claims generally have a 4-year limit.
These traps get harder to manage as your affairs grow more complex. Professional help is worth it when you face:
- Rapid revenue changes
- Multiple entities
- Employees or contractors
- Complex GST or overseas dealings
- Existing ATO debt
- Uncertainty about structure
VJM Global provides outsourced accounting, bookkeeping, payroll and tax compliance support to Australian businesses, and has served 250+ of them. Pricing is quoted by entity structure and scope. Outcomes depend on your records and circumstances, so no tax result is guaranteed.
Frequently Asked Questions
When should I file my quarterly taxes?
Quarterly obligations usually follow BAS reporting periods. Standard quarterly dates are 28 October, 28 February, 28 April and 28 July, but yours depends on your ATO reporting cycle.
Who is required to file a quarterly income tax return?
Australia has no universal quarterly income tax return. Businesses instead have quarterly BAS, GST, PAYG instalment or PAYG withholding obligations, plus an annual return.
Do LLCs pay taxes quarterly or annually?
The US LLC doesn't map onto Australian structures. Timing depends on whether you are a sole trader, partnership, company or trust, plus your registrations. Income tax is annual, with PAYG instalments during the year.
What tax deductions can I claim as a self-employed person?
Claim expenses that are business-related, not private, and backed by records. Apportion mixed use. Capital expenses are generally deducted over time. Check the ATO's business deductions guidance.
What is the difference between a BAS and a quarterly tax return?
A BAS reports GST and selected PAYG amounts during the year. The annual income tax return reports taxable income for the financial year. One doesn't replace the other.
Can I correct a mistake after lodging my BAS?
Some errors can be corrected on a later BAS, subject to time and value limits. Others need the original BAS revised. Check the ATO's correction rules or ask an authorised agent.
