BAS Countdown: 2026-27 BAS Due Dates for Sydney Business

Updated: November 2026

For hands-on help with this, see BAS lodgement Sydney.

The next BAS due date for most quarterly lodgers using a registered agent is 25 November 2026, for the July to September 2026 quarter, under the ATO lodgment program. If you lodge yourself, that quarter was due 28 October 2026. The October to December quarter is due 28 February 2027 for everyone, with no agent extension, and because 28 February 2027 is a Sunday, the next business day applies. This countdown lists every 2026-27 date, what happens if you miss one, and how to get the next BAS in on time.

What are the quarterly BAS due dates for 2026-27?

Standard due dates if you lodge yourself:

• July to September 2026: 28 October 2026.
• October to December 2026: 28 February 2027.
• January to March 2027: 28 April 2027.
• April to June 2027: 28 July 2027.

Online self-lodgers may get an extra two weeks for some quarters. Check the ATO due dates page for your situation.

What are the agent lodgment program dates?

If a registered tax or BAS agent lodges electronically for you, the ATO's 2026-27 lodgment program gives these dates for quarterly BAS:

• July to September 2026: 25 November 2026.
• October to December 2026: 28 February 2027 (no concession; next business day as it falls on a Sunday).
• January to March 2027: 26 May 2027.
• April to June 2027: 25 August 2027.

These dates generally only apply if your previous statement was lodged electronically. Ask your agent to confirm before you rely on them.

What if you lodge monthly?

Monthly BAS is due on the 21st of the following month. Businesses with GST turnover of $20 million or more must report monthly. For example, the October 2026 BAS is due 21 November 2026. If a due date falls on a weekend or public holiday, you can lodge and pay on the next business day.

What happens if you miss a BAS date?

• Failure to lodge penalty: one penalty unit of $364, from 1 July 2026, for each 28 days or part late, up to 5 units for a small business. Larger withholders face multiples.
• General interest charge: 11.51% a year for October to December 2026, compounding daily on unpaid amounts.
• No tax deduction for GIC from 1 July 2025.

If you have already missed one, see what to do if your BAS has not been lodged or our catch-up plan for several overdue BAS.

How do you get the next BAS in on time?

A simple countdown for each quarter:

• Throughout the quarter: reconcile weekly and capture receipts as they arrive.
• First week after quarter end: final reconciliations and GST check.
• Second week: draft BAS reviewed with you, with the amount payable confirmed.
• Third week: lodge, then schedule payment for the due date.
• Due date: payment made and lodgement receipt saved.

Our BAS lodgement service follows this routine, and our BAS deadline guide explains how the dates work.

What about super and payroll deadlines?

BAS is not the only date to track. Since 1 July 2026, Payday Super means super must reach employees' funds within 7 business days after each payday, rather than quarterly. See our guide to super payment deadlines.

What if you cannot pay by the due date?

Lodge on time anyway. If you owe $200,000 or less, you may be able to set up a payment plan online. Interest still applies to the unpaid balance.

What do most people miss?

The October to December quarter has no agent extension. Many businesses get used to the later agent dates and are caught out by 28 February, which comes straight after the Christmas shutdown. Start that BAS in January. Our Christmas shutdown checklist helps.

What should you have ready before your bookkeeper starts the BAS?

• Receipts and bills for the quarter uploaded to your receipt capture tool.
• Details of any large or unusual transactions, such as asset purchases or loans.
• Cash sales or takings not shown in the bank feed.
• Any changes to staff, wages or contractors during the quarter.
• Questions from your bookkeeper's weekly list answered.

The more of this is ready on the first day after the quarter ends, the earlier your BAS can be lodged and the earlier you know the amount to pay.

How do you set aside money for BAS?

A simple habit prevents most BAS stress: move the GST you collect, plus any PAYG withholding, into a separate bank account each week. Your bookkeeper can tell you the amount from the reconciled file. When the BAS is due, the money is already there. If you also pay PAYG instalments, include an estimate of those too.

Which other dates sit around BAS time?

• Super for every pay run, due to reach funds within 7 business days after payday.
• TPAR by 28 August each year if your business must lodge one.
• STP finalisation for employees at the end of each financial year.
• Any ATO payment plan instalment dates.

Put them all in one calendar so nothing is missed between BAS quarters.

How do you know the BAS was lodged?

Do not assume. After each due date, log into ATO Online services for business and check the activity statement shows as lodged. Ask your bookkeeper to send the lodgement receipt each quarter, and save it with your records. It takes two minutes and is the simplest way to catch a missed lodgement before penalties grow.

What if your business is new to BAS?

If you have just registered for GST, check your ATO account for your reporting cycle and first due date. Most small businesses report quarterly. Set up your Xero GST settings to match, connect bank feeds, and start capturing receipts from the first day, so your first BAS is built from complete records rather than a scramble at the end of the quarter.

FAQ

When is the next BAS due?

For quarterly lodgers using a registered agent, the July to September 2026 BAS is due 25 November 2026. The October to December 2026 BAS is due 28 February 2027, which moves to the next business day as it is a Sunday.

Does my agent get an extension on every quarter?

No. The October to December quarter has no lodgment program concession.

What if the due date is on a weekend?

You can lodge and pay on the next business day.

What is the penalty for a late BAS?

One penalty unit of $364 for each 28 days or part late, up to 5 units for a small business, plus interest on unpaid amounts.

Want your next BAS done early?

We reconcile, prepare and lodge your BAS well before the due date, for a fixed monthly fee.

Next step: send us a message and a real person replies within a few working hours, or book a free Xero Roast, a 15-minute plain-English review of your file with a fixed quote at the end. Our fixed monthly packs include a 4-hour reply guarantee, no lock-in and a 30-day money-back guarantee.

About Sydney Bookkeeper

Sydney Bookkeeper is the modern, fixed-price Sydney bookkeeper for businesses with staff that are tired of slow, hourly, jargon-spouting incumbents. We work with professional services firms, construction and property businesses, agencies, tech and ecommerce companies, hospitality groups, and health practices across Sydney. Monthly bookkeeping, BAS lodgement, payroll, and Xero file cleanups, all on fixed monthly pricing, no lock-in.

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The team uses a registered BAS Agent for all BAS and IAS lodgement services. Full registration details, agent particulars, and copies of the Tax Practitioners Board (TPB) Code of Professional Conduct, the TPB complaints process, and any conditions on the agent's registration are available on request by emailing hello@sydneybookkeeper.com. This content is general information only, written for Australian small and mid-market businesses. It does not constitute tax, financial product, or legal advice and should not be relied on as such. Tax obligations depend on your individual circumstances. For advice specific to your business, contact the team directly or consult a registered tax agent or licensed financial adviser. Sydney Bookkeeper is not a licensed tax agent or licensed financial adviser. Information was current at the time of publication and may change without notice. We review and update guides periodically.

Sources

• ATO, Due dates for lodging and paying your BAS: https://www.ato.gov.au/businesses-and-organisations/preparing-lodging-and-paying/business-activity-statements-bas/due-dates-for-lodging-and-paying-your-bas
• ATO, BAS agent lodgment program 2026-27: https://www.ato.gov.au/tax-and-super-professionals/for-tax-professionals/prepare-and-lodge/bas-agent-lodgment-program-2026-27
• ATO, Failure to lodge on time penalty: https://www.ato.gov.au/individuals-and-families/paying-the-ato/interest-and-penalties/penalties/failure-to-lodge-on-time-penalty
• ATO, General interest charge (GIC) rates: https://www.ato.gov.au/tax-rates-and-codes/general-interest-charge-rates
• ATO, Denying deductions for ATO interest charges: https://www.ato.gov.au/about-ato/new-legislation/in-detail/businesses/deny-deductions-for-ato-interest-charges
• ATO, Penalty units: https://www.ato.gov.au/individuals-and-families/paying-the-ato/interest-and-penalties/penalties/penalty-units
• ATO, Payment deadlines for Payday Super: https://www.ato.gov.au/businesses-and-organisations/super-for-employers/paying-super-on-payday/payment-deadlines-for-payday-super