Every date, every document, every decision.
A practical reference for the 2025–26 financial year and the start of 2026–27. Calendar, filing checklist, PAYG instalments, and a tax-impact comparison of the three main business structures. Updated for Payday Super (1 July 2026).
Filing checklist
What you'll need for individuals, sole traders, companies, trusts and partnerships — gathered before the appointment, not during.
Learn more PAYGEstimated payments
How PAYG instalments work, when to vary them, and the four quarterly dates to put on the calendar right now.
Learn more StructureStructure modelling
Sole trader vs company vs trust — we model the tax outcome so you can have the right conversation with your solicitor or specialist before they execute the change.
Learn moreThe 2025–26 tax calendar.
Every key date for BAS, PAYG, super, FBT and income tax. Updated where ATO adjusts due dates for weekends or public holidays.
| Date | Obligation |
|---|---|
| 28 October 2025 | Q1 BAS lodgement & payment (Jul–Sep 2025). Q1 Super Guarantee contribution deadline. |
| 25 November 2025 | Q1 BAS extended deadline (tax-agent clients). |
| 21st of each month | Monthly IAS lodgement & PAYG withholding payment for the prior month. |
| 28 January 2026 | Q2 Super Guarantee contribution deadline (Oct–Dec 2025). |
| 28 February 2026 | Q2 BAS lodgement & payment (Oct–Dec 2025). No tax-agent extension for Q2. |
| 31 March 2026 | Extended lodgement deadline for certain tax-agent clients (prior-year returns). |
| 28 April 2026 | Q3 BAS lodgement & payment (Jan–Mar 2026). Q3 Super Guarantee contribution deadline. |
| 15 May 2026 | Extended individual tax return deadline (tax-agent clients, 2024–25 FY). |
| 26 May 2026 | Q3 BAS extended deadline (tax-agent clients). |
| 30 June 2026 | End of 2025–26 financial year. Last day for pre-paid deductions, super contributions for deductibility, and asset purchases under the $20,000 instant asset write-off. |
| 1 July 2026 | PAYDAY SUPER COMMENCES. Super must be paid on payday, not quarterly. SBSCH closes. New STP reporting labels apply. |
| 14 July 2026 | Employers finalise STP income statements for 2025–26 FY. |
| 28 July 2026 | Q4 BAS lodgement & payment (Apr–Jun 2026). Q4 Super Guarantee contribution deadline (final quarter under old rules). |
| 25 August 2026 | Q4 BAS extended deadline (tax-agent clients). |
| 31 October 2026 | Individual tax return lodgement deadline (self-lodgers, 2025–26 FY). Must be on a tax-agent's client list by this date for extended deadlines. |
| 15 May 2027 | Extended individual tax return deadline (tax-agent clients, 2025–26 FY). |
Important note: under the new Payday Super rules from 1 July 2026, the quarterly super deadlines (28 October, 28 January, 28 April, 28 July) no longer apply. Super must be paid with each pay run and received by the employee's fund within 7 business days of payday.
Don't do this alone.
The 2025–26 financial year is the transition year for Payday Super. Get a registered BAS Agent on it before 30 June 2026, not after.