BAS Due Dates 2026-27

Quarterly BAS is generally due on the 28th of the month after the quarter ends. Monthly BAS is due on the 21st of the following month. Lodging through a registered BAS or tax agent usually adds about four weeks to the quarterly dates. Every 2026-27 date is below.

Quarterly BAS due dates 2026-27

• Footnote 1 - the Q2 surprise: the December quarter is already extended to 28 February for everyone because of the holidays, so there is no further agent concession for Q2. Businesses used to buying four extra weeks through their agent are regularly caught by this one.
• Footnote 2 - weekends and public holidays: if a due date falls on a weekend or public holiday, you can lodge and pay on the next business day. 28 February 2027 falls on a Sunday, so that quarter effectively lands on Monday 1 March 2027.

Super guarantee is the trap sitting alongside these dates. It falls due on 28 October, 28 January, 28 April and 28 July, never gets an agent extension, and late super triggers the much harsher super guarantee charge regime.

Monthly BAS due dates

Monthly BAS is due on the 21st of the following month, with no agent extension for monthly lodgers, except that small businesses lodging the December month electronically are sometimes given until 21 February.

Small businesses lodging the December month electronically are often given until 21 February, so check your own ATO online services account rather than assuming.

Do you get extra time with a BAS agent?

Usually yes. Registered BAS and tax agents lodge under the ATO's lodgment program, which gives their clients roughly four extra weeks on the September, March and June quarters. The catch is that the concession attaches to the agent's lodgment list, not to you personally: you have to be on that list before the deadline passes. Signing up the week after a due date does not retrospectively buy the extension, and the December quarter and monthly GST get no further concession at all.

Beyond the program dates, the ATO can grant a further deferral case by case if you or your agent ask before the due date passes with a genuine reason. Deferrals are never guaranteed, so ask early rather than after the date has gone. If you want to move onto an agent's list, the process takes a few minutes online: see how to nominate us as your tax agent.

TaxNudge lodges BAS for clients with the extended agent deadlines - get in touch. We handle single quarters and multi-quarter catch-ups through our overdue BAS and GST service on a fixed fee.

What happens if you lodge BAS late

Unreported PAYG withholding and GST also expose company directors personally through a director penalty notice. Each late BAS is a separate document with its own failure to lodge penalty: $364 for every 28 days (or part) it is late, capped at five periods, so up to $1,820 per BAS for a small entity. Four unlodged quarters means four separate caps. Unpaid amounts also accrue the ATO general interest charge, which compounds daily and is no longer tax deductible from 1 July 2025. Estimate your own exposure with the ATO late lodgment penalty calculator, and see the failure to lodge penalty guide for how remission requests work.

An overdue BAS also holds up any GST refund you are owed. If you are several quarters behind, you lodge oldest first so each quarter's GST position is right before the next, and a tax agent can reconstruct figures from bank and invoicing data - the same approach set out in doing a tax return without receipts. Our overdue BAS catch-up for business handles multi-quarter catch-ups, alongside the broader guide to overdue tax returns.

How to pay your BAS

The BAS due date is a lodge and pay date. You can pay by BPAY, Government EasyPay, credit or debit card (a surcharge applies), or direct credit, using the payment reference number on your statement. The full comparison is in how to pay the ATO. If you cannot pay in full, lodge on time anyway and put the balance on a plan - estimate the instalments with the ATO payment plan calculator. Lodging on time avoids the penalty entirely even when payment has to wait.

BAS calendar, penalty unit and GIC rates checked 14 August 2026 for the 2026-27 financial year.

General information only - not personal tax, financial or legal advice. Consider your own circumstances or speak to a registered tax agent. Remission of penalties or interest and payment plans are decisions of the ATO and outcomes can't be guaranteed.