2026 Tax Due Dates Australia: Avoid ATO Penalties and Stay Ahead of Every Deadline

Keeping on top of tax due dates is not just an administrative task. For individuals, sole traders and business owners, a missed lodgment or payment can disrupt cash flow, create avoidable follow-up work and lead to ATO interest charges or penalties.

The important point is that there is no single deadline that applies to every taxpayer. Your obligations depend on matters such as your GST reporting cycle, whether you employ staff, your business structure, whether you use a registered tax or BAS agent, and the due date printed on your ATO notice. Still, a clear calendar helps you plan ahead and avoid last-minute surprises.

Start with the due date shown on your ATO notice

This guide covers common Australian tax deadlines that fall during the 2026 calendar year. It is a practical planning tool, not a replacement for the date shown on your BAS, instalment notice, assessment or ATO online account.

A few rules are worth remembering:

• If a due date falls on a weekend or public holiday, you generally have until the next business day to lodge and pay.
• Lodging and paying are often due on the same date for activity statements, so do not assume that lodging on time allows you to pay later.
• Registered tax and BAS agents may have access to concessional lodgment schedules, but these dates are not automatic and can depend on the client’s circumstances and lodgment history.
• An extension of time should be requested before the due date where possible. It is much easier to manage a problem early than to explain an overdue obligation afterwards.

For October 2026, the key near-term dates for many small businesses are the monthly BAS due on 21 October 2026 and the quarterly BAS for the July to September quarter due on 28 October 2026.

BAS, GST and PAYG instalment due dates for 2026

Your BAS may include GST, PAYG withholding, PAYG instalments, fringe benefits tax instalments, fuel tax credits and other amounts. The reporting cycle matters because it determines how often you need to report and pay.

Quarterly BAS dates

For businesses reporting quarterly, the standard BAS due dates are 28 October, 28 February, 28 April and 28 July. In 2026, the practical calendar is:

The February deadline moved to Monday 2 March 2026 because 28 February 2026 fell on a Saturday. Eligible businesses that lodge their quarterly BAS online may receive an additional two weeks for some quarters, but this does not apply to the December quarter deadline and should not be assumed without checking your own BAS.

Monthly BAS dates

Monthly BAS lodgers generally need to lodge and pay by the 21st day of the following month. That means, for example, a September 2026 monthly BAS is generally due on 21 October 2026.

Where the 21st falls on a weekend or public holiday, the next business day rule applies. This affects some 2026 monthly dates, including:

• January 2026 BAS, due 23 February 2026 because 21 February fell on a Saturday.
• May 2026 BAS, due 22 June 2026 because 21 June fell on a Sunday.
• October 2026 BAS, due 23 November 2026 because 21 November fell on a Saturday.

Businesses with a GST turnover of at least $20 million are generally required to report GST monthly. Other businesses may choose monthly reporting, which can make GST and PAYG cash flow more regular but also creates more frequent reporting work.

Annual GST reporting

Annual GST reporting is only available to businesses that are voluntarily registered for GST and meet the relevant turnover conditions. The annual GST return is generally due on 31 October, or 28 February after the annual tax period if a tax return is not required at that earlier date.

As 31 October 2026 falls on a Saturday, a self-lodged annual GST return due at that point would generally move to Monday 2 November 2026.

Income tax return dates for individuals, sole traders and businesses

For most individuals and sole traders who prepare and lodge their own income tax return, the annual lodgment deadline is 31 October. In 2026, that date falls on a Saturday, so the practical deadline is Monday 2 November 2026.

If you lodge your own 2025–26 tax return by that deadline and receive a tax bill, payment is generally due by 21 November. Because 21 November 2026 is a Saturday, the practical payment date is Monday 23 November 2026.

Using a registered tax agent can provide a later lodgment date under the ATO’s lodgment program. However, you generally need to engage the agent before the self-lodgment deadline, and the later date varies depending on the taxpayer, entity type, prior-year lodgments and payment history. Do not wait until late October and assume a tax agent can simply move the deadline.

For companies, trusts, partnerships and SMSFs, income tax return due dates are more variable. They can be affected by the entity’s balance date, whether it is newly registered, whether it has overdue returns and whether it is on an agent’s lodgment program.

A sensible approach is to treat 30 June as the start of tax return preparation, rather than the start of tax return panic. Finalise bookkeeping, reconcile bank accounts and loans, review payroll records, collect deduction evidence and identify any capital gains or trust distribution issues well before your actual lodgment date.

Employer deadlines: STP, superannuation, FBT and contractor reporting

Employers have several deadlines that sit outside the usual BAS cycle. These are often missed because payroll, superannuation and fringe benefits tax are handled by different people or systems.

Single Touch Payroll finalisation

Employers using Single Touch Payroll generally need to make a finalisation declaration by 14 July each year. For the 2025–26 financial year, that means finalising employee income statements by 14 July 2026 unless the ATO has approved a later date.

This process confirms that the payroll information reported through STP is complete. Employees then use their income statement information when preparing their own tax returns.

Superannuation: an important 2026 transition

2026 is a significant year for employer super obligations. For the quarter ending 30 June 2026, the final quarterly super payment must be received by the employee’s super fund by 28 July 2026.

If that quarterly contribution was not paid on time, the employer needed to lodge a super guarantee statement and pay the super guarantee charge by 28 August 2026. A late super payment is not simply a minor timing issue, so it is important to obtain advice promptly if the deadline has been missed.

From 1 July 2026, the rules changed to Payday Super for relevant payments. Rather than relying on quarterly contribution deadlines, employers must generally ensure super payments reach the employee’s fund within seven business days after payday. This makes payroll processes, clearing house processing times and employee fund details much more important.

Fringe benefits tax

The FBT year runs from 1 April to 31 March, rather than matching the usual income tax year. An employer that has an FBT liability for the year ending 31 March 2026 generally needed to lodge and pay its FBT return by 21 May 2026.

A tax agent lodging electronically may have had a later deadline of 25 June 2026, subject to the agent lodgment arrangements. Businesses providing cars, entertainment, loans, expense reimbursements or salary-packaged benefits should review FBT well before the March year-end, not after it.

Taxable payments annual report

Businesses in certain industries that pay contractors may need to lodge a taxable payments annual report, commonly called a TPAR. The report is due by 28 August each year.

The reporting obligation can apply to businesses in industries such as building and construction, cleaning, courier services, road freight, information technology, security, investigation and surveillance. If your business engages contractors, it is worth checking whether TPAR reporting applies before August arrives.

A practical tax calendar for the rest of 2026

The following checklist is useful for many small businesses with employees and quarterly GST reporting.

October 2026

• 21 October: Monthly BAS for September, where applicable.
• 28 October: Quarterly BAS for July to September.
• Start reviewing the 2025–26 income tax return if you are lodging yourself.

November 2026

• 2 November: Self-lodged 2025–26 income tax return deadline for many individuals and sole traders.
• 23 November: Payment due date for many self-lodged 2025–26 tax returns that result in an amount payable.
• 23 November: Monthly BAS for October, where applicable.

December 2026

• 21 December: Monthly BAS for November, where applicable.
• Review payroll records, GST coding and contractor details before the year-end holiday period.
• Confirm that Payday Super processes are working correctly, particularly if payroll is processed early over Christmas and New Year.

A common mistake is treating a due date as the day to start preparing. Instead, build an internal deadline at least one week earlier. That gives you time to resolve missing invoices, bank-feed errors, payroll corrections or cash flow concerns before the formal deadline arrives.

What happens if you miss a tax deadline?

Missing a date does not always mean the same outcome, but it should never be ignored. The ATO may apply failure-to-lodge penalties, general interest charge on overdue amounts, or both depending on the obligation and circumstances.

General interest charge is calculated daily and compounds while an amount remains unpaid. It is also important to note that general interest charge and shortfall interest charge incurred on or after 1 July 2025 cannot be claimed as a tax deduction.

If you cannot pay in full, lodge on time where possible and contact the ATO before the due date. A payment arrangement may be available, but it does not necessarily stop interest from accruing. Early communication, accurate records and a realistic payment plan are usually far better than allowing debts and overdue lodgments to build up.

Consider a small trades business that lodges its September quarterly BAS close to the 28 October deadline. Its owner discovers that several supplier invoices have not been entered and the payroll figures do not match the bank account. Rather than guessing, the business should reconcile the records, lodge an accurate BAS as soon as possible and make contact early if payment will be difficult. Rushing an incorrect BAS can create more work than a properly managed delay.

Keep state tax obligations separate

This article focuses on common federal tax and superannuation dates. State and territory obligations, including payroll tax, land tax, transfer duty and certain registrations, have separate rules and deadlines that differ substantially across Australia.

For example, a business operating in New South Wales may have different payroll tax reporting requirements from a business operating in Victoria, Queensland or Western Australia. If you operate across state borders, own property through a trust or employ staff in more than one jurisdiction, your state tax calendar deserves the same attention as your ATO calendar.

Stay organised before the deadline becomes urgent

The best tax calendar is one that is connected to your bookkeeping and cash flow process. Set reminders before each BAS, keep superannuation and PAYG withholding funds separate from working capital where possible, and review your ATO account regularly for upcoming obligations.

The key takeaway is simple: know which deadlines apply to your circumstances, prepare early and act quickly if there is a problem. If you would like help managing BAS, payroll, tax returns, superannuation or business compliance dates, the team at can provide advice tailored to your situation.

This article is general information only and is not personal financial or tax advice. Speak with a registered tax agent or accountant, such as, about your specific circumstances.