BAS Lodgement Deadlines 2026: Key Dates for Melbourne Businesses

What are the quarterly BAS due dates for 2025-26?

For businesses lodging quarterly, the standard due dates are: Q1 (July–September 2025) due 28 October 2025; Q2 (October–December 2025) due 28 February 2026; Q3 (January–March 2026) due 28 April 2026; Q4 (April–June 2026) due 28 July 2026. Note that Q2 has a later deadline than other quarters due to the Christmas and New Year period — 28 February rather than 28 January. This is a common source of confusion for businesses that expect a consistent 28th-of-the-month pattern.

Do tax agents get extended lodgement dates?

Yes — registered tax agents and BAS agents receive extended lodgement dates for clients on their lodgement program. The standard agent extension for quarterly BAS is generally 25 days beyond the standard due date, subject to the ATO's current agent lodgement program. For Q1 2025-26, the agent extension is typically 25 November 2025; for Q3, it is 25 May 2026. Agent extensions are not automatic — you must be formally registered as a client with your agent before the original due date to access the extension. If you only engage an agent after the due date has passed, you will not receive the extension for that period.

What penalties apply for late BAS lodgement?

The ATO's failure-to-lodge (FTL) penalty is calculated in penalty units. As of 2025-26, one penalty unit is $330. For small entities (turnover under $1 million), the FTL penalty is 1 penalty unit ($330) for each 28-day period (or part thereof) the lodgement is overdue, capped at 5 penalty units ($1,650). For medium entities ($1 million–$20 million turnover), the rate is 2 penalty units ($660) per period, capped at $3,300. For large entities, it is 5 penalty units ($1,650) per period, capped at $8,250. Separate general interest charges (GIC) apply on any unpaid tax amounts, currently calculated at around 11%–12% per annum.

How can Melbourne businesses avoid missing BAS deadlines?

The most reliable approach is to reconcile your accounts monthly rather than leaving everything until the quarter end. This means your BAS should take minutes to prepare rather than days. Set a calendar reminder two weeks before the due date — not on the due date — to give yourself time to gather any missing information. If you use accounting software like Xero or MYOB, configure automated bank feeds and code transactions regularly so the BAS figures are always current. For businesses with complex GST situations (mixed-supply retailers, property transactions, or imported services), engage a BAS agent to prepare and lodge on your behalf so agent extensions are available as a buffer.

What if I cannot pay the BAS amount on time?

Lodging your BAS on time, even if you cannot pay the full amount, significantly reduces your exposure to penalties. The ATO distinguishes between failure to lodge and failure to pay — the FTL penalty applies to late lodgement, while GIC interest applies to unpaid amounts. If you are in financial difficulty, contact the ATO before the due date to discuss a payment plan. The ATO's automated payment plan tool allows arrangements up to 24 months for eligible debts without requiring a phone call. Proactive communication almost always results in better outcomes than ignoring the deadline.