Don't miss a GST deadline. Our comprehensive guide shows you exact filing dates, quarterly periods, STP requirements, and penalties for late submissions in 2026-27.
4
Quarterly Periods
7
Days to File
STP
Required Software
15%
Max Penalty
Covers: 1 January – 31 March 2026
Deadline: 7 May 2026
Must file and pay GST by this date using Single Touch Payroll software.
Covers: 1 April – 30 June 2026
Deadline: 7 August 2026
Second quarterly submission. Payment must clear by deadline date.
Covers: 1 July – 30 September 2026
Deadline: 7 November 2026
Third BAS (Business Activity Statement). Allow time for processing and payment.
Covers: 1 October – 31 December 2026
Deadline: 7 February 2027
Final quarterly return. Final deadline extends into next calendar year.
Most GST-registered businesses file quarterly returns. Four GST periods per calendar year, each ending on the last day of months 3, 6, 9, and 12. Returns are due 7 days after the period ends.
Businesses can elect for monthly returns if they prefer more frequent filing. This may help cash flow management and reclaim input GST faster. 12 returns per calendar year, due 7 days after each month ends.
Only available if you're not part of the Single Touch Payroll scheme. One return per calendar year, due 7 days after 31 December. Limited to businesses with lower turnover or specific circumstances.
Mandatory for: GST-registered businesses with turnover above A$85,000 (from April 2024). Mandatory for all registered businesses from 1 April 2026.
ATO uses a points-based surcharge system: Late returns accumulate penalty points. After reaching a threshold, a surcharge is applied to the GST due. The surcharge percentage increases with repeat offences.
5% surcharge after 12 months
1 penalty unit (currently $222 for small entities) per 28-day block, capped at 5 units
10% surcharge after 24 months
Higher penalty units accumulate the longer a BAS is overdue, plus the General Interest Charge
15% surcharge after 24 months
Repeated late lodgement may trigger an audit and additional administrative penalties
Set calendar reminders 2 weeks before the BAS (Business Activity Statement) deadline. This gives you time to gather records and resolve any issues.
Update your STP software weekly with invoices and receipts. Don't wait until the deadline to enter data.
Use STP-compatible accounting software that handles calculations automatically and integrates with ATO.
Consider using an accountant if you're unsure about GST calculations or compliance requirements.
Before submitting, verify all figures, especially GST-exempt sales and input GST claims.
Arrange payment 2-3 days before the deadline to account for bank processing time.
Launch your Single Touch Payroll accounting software (Xero, QuickBooks, Sage, etc.). Ensure all records are current and complete.
Choose the GST period you're filing for (e.g., Q1 ending 31 March). The software will auto-populate the deadline date.
Review your BAS labels: G1 (total sales), 1A (GST on sales), 1B (GST on purchases), and 7 (net GST owing or refundable).
Click "Submit to ATO" in your STP software. Your software will securely send the return via the ATO API. You'll receive a confirmation reference.
Pay any GST amount owing (or wait for the refund) by the BAS due date. Pay via BPAY, direct debit, or the ATO portal.
Payment Methods: Online (ATO Payments Service), Direct Debit, CHAPS transfer, BACS transfer. Allow 2-3 days for bank processing.
Yes, you can change your BAS (Business Activity Statement) period. Contact ATO or apply through your online GST account. Changes typically take effect from the next tax period. You'll need to provide a valid business reason.
If you're owed a refund (input GST exceeds output GST), ATO will typically process this within 30 days if you've submitted correctly. You can request a direct credit to your bank account or carry it forward to the next period.
Filing is submitting your return to ATO. Paying is sending the GST amount due. Both must be completed by the deadline. You must file before you can pay. If you file but don't pay, you'll face late payment penalties.
Yes. If you make an error within 12 months, submit an amended return. For larger corrections, you may need to contact ATO directly. Always keep documentation of amendments in case of audit.
Yes. Keep digital copies of all supporting invoices and receipts for at least 6 years. Scan physical receipts or use OCR software. ATO may request these during an audit to verify your GST figures.
Use our Reverse GST Calculator to check your GST calculations, or browse our other tools designed for Australian businesses.