Ultimate BAS Due Dates 2026: Avoid ATO Penalties!

Australians who run a business quickly learn that the Business Activity Statement is much more than a form; it is the ATO’s primary touch-point for collecting Goods and Services Tax, Pay As You Go withholding, PAYG instalments, Fringe Benefits Tax instalments and several other levies. Missing a BAS deadline can trigger penalties, interest charges and unwanted scrutiny. Meeting every lodgement and payment date, on the other hand, keeps cash flow predictable and demonstrates sound governance to lenders, investors and the Tax Office alike. The 2026 calendar year presents the usual spread of monthly, quarterly and, for a small cohort, annual reporting obligations. It also contains leap-year timing quirks and a smattering of public holidays that push several dates forward. This comprehensive guide explains every BAS due date for 2026, the legal framework that underpins those deadlines and the practical steps any Australian enterprise can take to lodge on time and avoid penalties.

What a BAS is and who has to lodge in 2026

A Business Activity Statement is the periodic return that conveys your indirect tax position to the Commissioner of Taxation under section 31-5 of the A New Tax System (Goods and Services Tax) Act 1999. If you are registered for GST, you must lodge a BAS even if you have nothing to report for a particular period; the return simply shows zeros. You may also need to complete a BAS if you withhold PAYG amounts from wages, pay instalments of income tax, or report wine, fuel or luxury car tax. The obligation applies equally to sole traders, companies, trusts, not-for-profits, partnerships and government entities. The only way to avoid a BAS obligation is to surrender the underlying registration, such as cancelling GST if annual turnover reliably sits below the $75,000 threshold ($150,000 for not-for-profits). Most businesses lodge either monthly or quarterly depending on turnover and cash-flow preference, but the ATO still allows a limited annual option for entities with GST turnover under $75,000 that are not voluntary monthly reporters. Those rules have not changed for the 2026 income year, and the Taxation Administration Act 1953 continues to empower the Commissioner to defer a due date where circumstances justify an extension.

Quarterly BAS due dates for the 2026 calendar year

More than sixty per cent of Australian small and medium enterprises opt for quarterly reporting because it balances regular cash flow monitoring with administrative efficiency. The ATO sets the standard due date on the twenty-eighth day of the month after the quarter ends. When that date falls on a weekend or national public holiday, the due date rolls to the next business day. Registered BAS agents enjoy an additional four-week concession for the December and March quarters and two extra weeks for the June and September quarters under the BAS Agent Lodgment Program. The following table summarises every quarterly deadline for 2026.

Several nuances sit behind these dates. First, 28 January 2026 is a Wednesday that follows the Australia Day public holiday on Monday 26 January, yet the ATO does not provide extra time because the due date already sits after the holiday. Second, the June quarter agent concession ends on Tuesday 11 August 2026 under the lodgment program’s published schedule, providing only fourteen extra calendar days compared with the four weeks available for earlier quarters. Agents and clients sometimes miss that tighter timeframe, so diarising the June quarter today helps prevent a stressful scramble next year.

Monthly BAS due dates for 2026

Businesses with GST turnover of $20 million or more must lodge monthly; many smaller enterprises choose the monthly cycle because it tightens cash-flow alignment or accelerates refunds. Monthly BAS returns are due on the twenty-first day of the month after the reporting period. The only routine exception is the December activity statement, which receives a guaranteed extension to 21 February of the following year to accommodate the summer break. In 2026, Australia experiences a leap year boundary but no additional ATO concessions. The table below sets out each monthly due date.

Dates marked with an asterisk reflect a shift to the next business day because the twenty-first falls on a weekend or a national holiday. For example, 21 June 2026 lands on a Sunday, so the due date automatically moves to Monday 22 June. That adjustment happens automatically, and no application for deferral is required.

Annual GST and PAYG reporting options

Small entities with GST turnover below $75,000, or $150,000 for not-for-profits, may elect to lodge an Annual GST Return instead of quarterly or monthly BAS forms. The return combines the BAS and the income tax return. Payment of actual GST liability occurs once a year, although instalments may still apply. The due date for an Annual GST Return aligns with the income tax return deadline, which for most self-prepared small businesses is 31 October following the financial year. When the business uses a registered tax agent, that deadline often extends to 15 May of the next calendar year. Choosing the annual cycle can ease record-keeping but removes the cash-flow advantage of frequent refunds. The PAYG instalment optional annual reporting method also remains available in 2026 for entities whose most recent notional tax is below $8,000 and that meet several other tests. Lodging annually means the BAS label structure changes, so software settings should be reviewed before the first annual cycle commences.

Agent concessions and how to qualify in 2026

The BAS Agent Lodgment Program exists under section 162-5 of the Taxation Administration Act 1953, giving the Commissioner the discretion to defer due dates for clients of registered agents. To access the concession, a business merely needs to have an engagement letter or other written authority on file with a registered BAS or tax agent. No separate application is required. The agent then submits the BAS through the online services portal under their registration number, and the extended due date applies automatically as long as the lodgement program remains current. If a business changes agents mid-year, the new agent must add the entity to their client list at least twenty-four hours before lodging to ensure the concession appears. The ATO monitors the overall on-time filing record of each BAS agent, so it can withdraw concessions from an agent whose practice repeatedly files late. Maintaining accurate, timely client records therefore protects both the firm and its clients.

Penalties for late lodgement and payment

When a BAS arrives after the due date, the ATO imposes a failure-to-lodge penalty based on penalty units. At 1 July 2026 one penalty unit is legislated at $313, and the ATO applies one unit for every twenty-eight days or part thereof that the statement remains outstanding, up to a maximum of five units. Entities whose assessable income exceeds $1 million multiply the base penalty by two, and those above $20 million multiply it by five. Interest on late payments, called the General Interest Charge, accrues daily at a variable rate published quarterly; recent history places that figure around 11 per cent per annum. The table below illustrates potential costs for a small business.

The Commissioner has power to remit a penalty wholly or in part where extenuating circumstances exist, such as serious illness, natural disaster or system outages. Payment plans can pause further recovery action but do not stop interest. Consequently, the cheapest option is always on-time lodgement even if the payment itself requires a short-term financing arrangement.

Public holidays, weekends and what happens when a due date shifts

Australian public holidays interact with BAS due dates in a predictable way. When the standard due date falls on a Saturday, Sunday or a national public holiday such as Australia Day or Anzac Day, the ATO grants an automatic extension to the next business day. State-based holidays like the Queen’s Birthday or Labour Day do not trigger a national extension, so businesses in the affected jurisdiction must lodge earlier or rely on the agent concession. In 2026 the major date affected is 21 June, which shifts to 22 June because the twenty-first is a Sunday. Other public holidays, including Anzac Day on Saturday 25 April 2026, do not coincide with BAS due dates, so no automatic concessions arise.

First-time lodgers and changing reporting cycles

A newly registered entity receives its first BAS after the ATO processes the ABN and GST registration. If the business registers partway through a quarter, the first reporting period may be a short period ending on the next regular cycle date. For instance, a company registering for GST on 15 February 2026 will lodge its first BAS for 15 February to 31 March, due on 28 April. The ATO allows a change in reporting frequency once per year in most cases. A request to shift from monthly to quarterly, or vice versa, must be lodged before the first day of the next tax period. Therefore, a taxpayer wanting monthly reporting from 1 July 2026 must apply by 30 June 2026. Software settings within cloud accounting platforms such as Xero or MYOB must then be updated to match the new cycle to avoid misreporting.

Practical tips for stress-free BAS preparation

Consistent record-keeping remains the cornerstone of smooth BAS lodgement. Reconciling bank accounts weekly, rather than quarterly, avoids the last-minute scramble and minimises data-entry errors that lead to amended statements. Modern accounting software can automate GST coding rules, but human oversight is still critical. Running a quick trial balance review before each BAS cycle helps to spot misallocations such as high GST on expense claims or negative PAYG withholding. Where cash flow is tight, setting aside the GST component of every sale into a dedicated bank account keeps funds available when the BAS falls due. Finally, calendar integrations can push automated reminders one week and one day before each deadline, reducing the chance of oversight, especially in months like February where the standard timeline is shorter.

Key takeaways for Australian businesses in 2026

The BAS framework for 2026 mirrors previous years, yet subtle calendar shifts, agent concession variations and penalty inflation all combine to make deadline management more important than ever. The must-remember dates are 28 January, 28 April, 28 July and 28 October for standard quarterly lodgers, with agent clients receiving up to four extra weeks in the March quarter but only two in June. Monthly lodgers face the familiar rhythm of the twenty-first, with public holidays nudging May, June, November and December statements by a day or two. Failure-to-lodge penalties now start at $313 and can rise above $1,500 for chronic lateness, while interest continues to accrue at double-digit annual rates. Businesses that engage a registered BAS agent, reconcile accounts weekly and diarise every due date position themselves for a stress-free 2026, leaving more time to focus on growth.

Disclaimer and where to find official guidance

This article provides general information only and does not constitute tax advice. Always consider your circumstances and consult a registered BAS or tax agent before making decisions. Official guidance, including the full BAS Agent Lodgment Program, penalty rates and due dates, is available on the Australian Taxation Office website at ato.gov.au.