BAS Lodgement Due Dates 2026 — Quarterly & Monthly Deadlines

Quarterly BAS Due Dates — 2025–26 Financial Year

Most small businesses with a GST turnover below $20 million lodge BAS quarterly. The table below shows deadlines for the 2025–26 year (1 July 2025 – 30 June 2026).

Note: When a deadline falls on a weekend or public holiday, the due date moves to the next business day. Confirm exact dates with the ATO or your agent each year.

Quarterly BAS Due Dates — 2026–27 Financial Year

Monthly BAS Due Dates

Businesses with a GST turnover of $20 million or more must lodge BAS monthly. Monthly BAS is due on the 21st of the following month in most cases.

December is an exception — the December BAS is due 21 January, giving businesses extra time over the holiday period.

Annual BAS — Who Qualifies and When It's Due

Businesses voluntarily registered for GST with a turnover below $75,000 may be eligible to lodge an annual BAS instead of quarterly. The annual BAS covers the full financial year (1 July – 30 June) and is due by 31 October, or later if lodged through a registered agent.

What Happens If You Miss a BAS Deadline?

The ATO charges Failure to Lodge (FTL) penalties for late BAS submissions. Penalties are calculated based on the size of the business and how late the lodgement is.

Penalties accumulate each 28-day period the BAS remains unlodged, capped at five penalty units (approximately 26 weeks). A registered BAS agent can often negotiate remission of FTL penalties for first-time or isolated late lodgements — but this is not guaranteed.

How to Never Miss a BAS Deadline

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  Use a registered BAS agent: Extended deadlines give you significantly more time. Most quarterly lodgements are due 4–8 weeks later through an agent than self-lodging.
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  Set calendar reminders: Add every BAS due date to your calendar at the start of the financial year. Set reminders 3 weeks before each deadline to gather records.
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  Keep your accounts current: Businesses that reconcile bank accounts monthly have BAS figures ready well before deadline. Leaving reconciliation until BAS time creates pressure.
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  Use cloud accounting software: Xero, QuickBooks, and MYOB can generate a BAS summary with one click if your accounts are reconciled — removing most of the manual work.
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  Know your lodgement category: Confirm with your accountant whether you are quarterly, monthly, or annual — and whether you qualify for electronic lodgement dates.