For most Australian small businesses, the BAS payment is one of the four or five biggest cash outflows of the quarter. It also has the strictest deadline — pay late and the ATO starts the general interest charge clock the same day.

What surprises a lot of business owners is that BAS lodgment dates and BAS payment dates are the same date. There is no grace period between lodging and paying. The moment your BAS is due, the payment is due too.

This guide lists every 2026 BAS payment date (quarterly and monthly, standard and tax-agent extended), explains what happens if you can’t pay on time, and walks through how to set up an ATO payment plan without triggering a Failure to Lodge penalty. If you’d rather get straight to a tailored answer, our team at Trinity Accounting Practice can take it off your hands.

BAS Payment Dates = BAS Lodgment Dates

The first and most important thing to know: your BAS payment is due on the same day you have to lodge it. The ATO does not separate “lodge by X” and “pay by Y” the way some private creditors do.

If your BAS shows a refund, you don’t have a payment obligation — but you still have to lodge on time to get the refund processed.

2026 Quarterly BAS Payment Dates — Standard ATO

If you lodge your own BAS (no registered tax or BAS agent):

Q2 FY2026 (Oct–Dec 2025) — pay by 28 February 2026
Q3 FY2026 (Jan–Mar 2026) — pay by 28 April 2026
Q4 FY2026 (Apr–Jun 2026) — pay by 28 July 2026
Q1 FY2027 (Jul–Sep 2026) — pay by 28 October 2026

2026 Quarterly BAS Payment Dates — Via Tax / BAS Agent

If a registered tax or BAS agent lodges your BAS, three of the four quarters get an automatic four-week extension. Q2 does not — it already has the Christmas concession.

Q2 FY2026 — pay by 28 February 2026 (no extra extension)
Q3 FY2026 — pay by 26 May 2026 (extended)
Q4 FY2026 — pay by 25 August 2026 (extended)
Q1 FY2027 — pay by 25 November 2026 (extended)

Important: to qualify for the extension, you must already be on the agent’s lodgment list before the standard due date. Engaging a tax agent the day after the original due date does not retroactively give you the extension.

2026 Monthly BAS Payment Dates

Monthly lodgers (mandatory for businesses with $20m+ GST turnover, or by election) pay on the 21st of the following month. There is no tax-agent extension on monthly BAS — same date whether you lodge yourself or through an agent.

Jan 2026 BAS — pay by 21 February 2026
Feb 2026 BAS — pay by 21 March 2026
Mar 2026 BAS — pay by 21 April 2026
… and so on through the year

Annual BAS Payment Date

Some small businesses can lodge an annual BAS instead of quarterly — typically those that have voluntarily registered for GST but have turnover under the $75,000 threshold. The annual BAS payment is due on 31 October, or with the lodgment of the annual income tax return.

What Happens If You Pay Late

Two things kick in immediately:

General interest charge (GIC) on the unpaid amount, compounding daily from the day after the due date. The GIC rate is set each quarter by the ATO and is usually several percentage points above the cash rate. It is also tax deductible in the year it accrues — but that doesn’t make it cheap.
Failure to Lodge (FTL) penalty — but only if you also lodged late. If you lodged on time and just paid late, you are charged GIC only.

This is the most important behavioural rule we drill with clients: even if you cannot pay, always lodge on time. Lodging triggers the GIC clock — but it stops the FTL penalty from running.

How to Pay Your BAS

The ATO accepts BAS payment via:

BPAY using the Biller Code shown on your BAS and your unique Payment Reference Number (PRN).
Direct credit (EFT) to the ATO’s bank account using your PRN as the reference.
Credit or debit card via the ATO’s payment portal — note the card surcharge.
Direct debit — useful if you want to schedule the payment exactly on the due date and not lose interest on your cash.
In person at Australia Post (with the original BAS payment slip and Bpay barcode).

Always use your Payment Reference Number from the BAS itself. The PRN changes for each BAS. Paying with last quarter’s PRN sends the money to the wrong period and creates a mess that takes weeks to unwind.

What If You Can’t Pay on Time?

If cash flow is tight, the ATO is generally pragmatic — provided you act before the due date, not after.

Lodge the BAS on time. This is non-negotiable. It stops the FTL penalty from running.
Pay what you can. Even part payment reduces the balance the GIC is calculated on.
Set up a payment plan. Small businesses with debts under $200,000 can usually arrange a payment plan online via myGov or via the ATO Business Portal. For amounts above that, or for repeat plans, the ATO usually wants a phone conversation.
Stay on the plan. Default once and the ATO can cancel the plan, escalate collection, and (in some cases) issue a Director Penalty Notice. Don’t let that happen.

The Common BAS Payment Mistakes We See

Lodging on time, paying a week late, expecting no consequences. The GIC starts the day after the due date — even one day late.
Using last quarter’s PRN. The payment vanishes into the wrong period. It is recoverable, but it is painful.
Paying the wrong amount because the BAS hasn’t been reviewed. Errors in GST coding mean you either overpay (your cash, gone unnecessarily) or underpay (you’ll owe the rest plus interest later).
Ignoring an ATO reminder until “next week.” ATO reminder letters escalate. The third one usually mentions garnishee notices. By that point you have already attracted GIC for weeks.

A Trinity insight from 22 years in practice

The biggest cash-flow improvement we have ever made for a Sydney small business client was not chasing more revenue. It was building a simple weekly “BAS savings” transfer — a fixed percentage of each week’s takings into a separate bank account, not touched until BAS day. The math is unglamorous, but it converts BAS from a panicked scramble every quarter into a calm transfer. If your business runs hot on cash, this single change is worth more than any tax planning we can do.

What This Means for You

If you self-lodge: diarise the 28th of February, April, July and October. Set a separate transfer-savings reminder for the day after each pay run.
If you lodge through a tax agent: confirm in writing that you are on the agent’s lodgment list before each standard due date. The extension only applies if registration is done in time.
If you are struggling to pay: lodge anyway, then engage the ATO before the due date passes. Avoidance makes everything worse — engagement is always cheaper.

How Trinity Can Help

Trinity Accounting Practice is a registered tax agent based in Beverly Hills, Sydney, with 22 years of experience helping NSW businesses manage BAS lodgment, payment timing, and ATO payment plans when needed. If you want the whole BAS cycle managed end-to-end — including the tax-agent extension and a cash flow approach that means BAS day is no longer painful — we can take it on.

Book a 30-minute BAS and cash flow review with the Trinity team →

General advice only. This article contains general information current as at May 2026 and does not constitute tax, financial or legal advice. It does not take into account your personal circumstances, objectives, or needs. BAS payment dates, GIC rates, and ATO payment plan terms can change — always verify on ato.gov.au. Before acting on any information in this article, you should consider its appropriateness to your situation and seek professional advice from Trinity Accounting Practice or another qualified adviser.