Every BAS deadline for FY 2026-27, adjusted for weekends. Aligned to ATO standard due dates.
Bookmark this page now. Dates are based on ATO rules as of January 2026. Always verify at ato.gov.au.
Eligibility: GST turnover under $20 million (based on projected turnover, not just historical).
Typical business: Most SMEs.
Note: Voluntary monthly lodgement can improve cash flow predictability if you prefer smaller, more frequent payments.
Eligibility: GST turnover $20 million or more, or PAYG withholding exceeds $25,000 annually. This roughly equates to an annual wage bill of $200,000 or more.
Typical business: Larger businesses and those with high employee counts.
Note: The ATO can direct you to monthly reporting regardless of turnover, particularly if you have significant PAYG withholding obligations.
Eligibility: Voluntary GST registration with turnover under $75,000 ($150,000 for non-profits).
Typical business: Sole traders and micro businesses with low transaction volumes.
Your reporting frequency can change mid-year if your circumstances change or the ATO directs a different frequency.
You must be registered with an agent before the quarter ends to claim their extension for that quarter. Q2 has no additional agent extension because the existing December buffer is built into the ATO lodgement program.
Public holidays can differ by state, but the ATO uses standard national processing dates for BAS deadlines.
Self-lodger due: 28 October 2026 (Wednesday)
Agent electronic due: 25 November 2026 (Wednesday)
Self-lodger due: 28 February 2027 falls on Sunday, shifts to 1 March 2027 (Monday)
Agent electronic due: 28 March 2027 falls on Sunday, shifts to 29 March 2027 (Monday)
Both Q2 dates shift due to weekend scheduling. Plan your February and March cash flow early.
Self-lodger due: 28 April 2027 (Wednesday)
Agent electronic due: 26 May 2027 (Wednesday)
Self-lodger due: 28 July 2027 (Wednesday)
Agent electronic due: 25 August 2027 (Wednesday)
Q4 coincides with EOFY pressure. Ensure super contributions and asset purchases are finalised before 30 June to avoid last-minute BAS complications.
Monthly lodgers do not receive agent extensions.
Important: Your GST accounting method (cash or accrual) determines which sales and purchases belong in each period, but it does not change the due date itself.
The standard monthly BAS due date is always the 21st of the following month, except where adjusted for weekends or the December extension.
Due: 21 August 2026 (Friday)
Due: 21 September 2026 (Monday)
Due: 21 October 2026 (Wednesday)
Due: 21 November 2026 falls on Saturday, shifts to 23 November 2026 (Monday)
Due: 21 December 2026 (Monday)
December 2026 activity due: 22 February 2027 (Monday). This is the ATO Christmas extension.
January 2027 activity due: 22 February 2027 (Monday). Same date as December.
Two BAS lodgements are due on the same day. Plan cash flow early. If your typical monthly BAS is $15,000, you need $30,000 available by late February.
February 2027 activity due: 21 March 2027 falls on Sunday, shifts to 22 March 2027 (Monday)
March 2027 activity due: 21 April 2027 (Wednesday)
April 2027 activity due: 21 May 2027 (Friday)
May 2027 activity due: 21 June 2027 (Monday)
June 2027 activity due: 21 July 2027 (Wednesday)
Not every label appears on every BAS. You only see what applies to your registration.
1A is GST collected on sales. 1B is GST paid on purchases.
Reconciliation check: Match to your accounting software GST report for the period.
W1 is gross wages paid. W2 is tax withheld from those wages.
Reconciliation check: Must equal your STP year-to-date figures for the period. Rounding differences usually indicate payroll timing issues, not GST errors.
Example: If your W2 (tax withheld) is $15,000 for the quarter, your STP year-to-date withholding for that period should show the same $15,000.
These are your pre-paid income tax instalments. You can vary these if your income has changed significantly. Not all businesses have PAYG instalments, so T7 and T8 may not appear on your BAS.
Reconciliation check: Review each quarter. If your income has dropped, vary downward. Note that downward variations require a reasonable basis to avoid underpayment penalties.
You can vary online via your ATO Online Services account before the due date.
5 is Wine Equalisation Tax. 5A is Fuel Tax Credits.
These apply only to specific industries. If you are eligible, claim via BAS and review annually.
Complete these checks before every lodgement.
Are all invoices, receipts, and bank transactions for the period coded in your accounting software?
Does your software GST setting (cash or accrual) match your ATO registration? Mismatches cause timing errors that trigger ATO queries.
Does your W2 figure equal your STP year-to-date withholding for the period? If not, investigate before lodging.
Has your income changed significantly? Should you vary T7 or T8? Submit variations before the due date. Remember that downward variations require a reasonable basis.
No activity this period? You still must lodge a nil BAS. Failure to Lodge penalties apply regardless of whether you owe money.
Run your BAS preview or GST summary report and confirm no uncoded transactions or GST mismatches exist. In Xero, this is the BAS Preview report. In other software, run your equivalent GST or profit and loss report for the period.
Document any variances before lodging. Save your reconciliation reports for audit readiness.
The Failure to Lodge (FTL) penalty starts at approximately $330 per 28-day period for small entities and is capped after a certain number of periods. Penalty unit amounts are indexed and change over time.
Voluntary disclosure of errors can reduce penalty severity.
General Interest Charge (GIC) applies at approximately 11 percent per annum on outstanding amounts.
Director Penalty Notices make company directors personally liable for unpaid PAYG withholding and super guarantee amounts. This applies to company directors, not sole traders.
Always lodge on time, even if you cannot pay the full amount. Contact the ATO immediately to arrange a payment plan. GIC still applies to unpaid amounts, but you avoid the heavier FTL penalties and demonstrate good faith.
If you realise you will be late, lodge immediately via ATO Online Services or through your agent. Then call the ATO business line to discuss a payment plan before they contact you.
Using a registered BAS or tax agent with electronic lodgement provides several benefits.
Extra time on quarterly BAS. You receive an additional four weeks on most quarterly deadlines. You must be on their client list before the quarter ends to claim the extension. Note that monthly BAS does not receive agent extensions.
Professional review. Agents catch errors before the ATO does, reducing amendment requests and audit risk.
Audit trail. Proper documentation if the ATO queries your lodgement.
Peace of mind. Compliance is handled while you focus on running your business.
Cost perspective. The cost of an agent is often less than the value of your time spent scrambling, plus the risk and cost of a last-minute error. One quarterly extension can save more in avoided penalties and recovered time than the annual agent fee.
Scale Suite provides embedded finance teams for Australian SMEs. We handle BAS preparation, lodgement, and reconciliation as part of our monthly service.
What we deliver:
Our Chartered Accountant oversight gives you compliance confidence without hiring internal staff.
Contact us to discuss how we can make BAS deadlines effortless.
Quarterly BAS is due 28 October 2026, 28 February 2027 (shifts to 1 March), 28 April 2027, and 28 July 2027 for self-lodgers. Monthly BAS is due the 21st of the following month. Agent electronic lodgement receives an additional four weeks for quarterly BAS.
December 2026 monthly BAS is due 22 February 2027 after weekend adjustment. This is the ATO Christmas extension. The standard 21 January due date does not apply.
The ATO provides a Christmas concession extending the December BAS due date. Since both December and January BAS fall due on 21 February 2027, which shifts to 22 February, two months of GST and PAYG withholding are payable on the same day.
Self-lodgers must meet the standard 28th of the month deadline. Registered BAS or tax agents with electronic lodgement receive an additional four weeks for most quarters. You must be registered with the agent before the quarter ends to claim their extension.
Yes. Even if your business had no income or expenses, you must lodge a nil BAS. Failure to Lodge penalties apply regardless of whether you owe money.
The ATO applies a Failure to Lodge penalty starting at approximately $330 per 28-day period for small entities. Penalties are capped after a certain number of periods. General Interest Charge also applies to any unpaid amounts.
Lodge on time even if you cannot pay. Contact the ATO immediately to arrange a payment plan. GIC still applies to unpaid amounts, but you avoid the heavier FTL penalties and demonstrate good faith.
If your GST turnover is under $20 million, you can generally lodge quarterly. If your turnover exceeds $20 million or your PAYG withholding exceeds $25,000 annually, you may need to lodge monthly. The ATO can also direct you to monthly reporting regardless of turnover.
Q2 BAS (October to December) does not receive an additional agent extension beyond the standard dates because the ATO's existing December buffer is built into the lodgement program.
Yes. If your turnover exceeds thresholds or the ATO directs monthly reporting, your frequency can change during the year. Check your ATO registration if you are unsure of your current requirements.
Q4 BAS (April to June 2027) is due 28 July 2027 for self-lodgers and 25 August 2027 for agent electronic lodgement.
Common labels include 1A and 1B for GST, W1 and W2 for PAYG withholding, and T7 and T8 for PAYG instalments. Not all labels appear on every BAS. You only see what applies to your registration.
Last updated: January 2026
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