BAS due dates 2026–27: Lodgement calendar for Australian accounting firms
BAS due dates for 2026–27 are not one-size-fits-all for Australian accounting firms. Quarterly, monthly and annual clients follow different timelines, while registered-agent concessions, weekends and public holidays can change the date your firm works towards.
That makes deadline planning more than a calendar exercise. Your team needs to know which clients are due when, what preparation must be completed before review, and where delegated support can reduce pressure before lodgement.
This blog breaks down the 2026–27 BAS calendar, key concessions, late-lodgement risks, internal cut-offs and practical planning steps for managing BAS workloads across your client portfolio.
Key takeaways
Quarterly BAS follows the usual 28 October, 28 February, 28 April and 28 July cycle, with weekend and public-holiday adjustments where relevant.
Eligible registered-agent clients can receive later dates for Q1, Q3 and Q4. Q2 receives different treatment.
Monthly BAS is due on the 21st of the following month, while annual GST reporting follows separate rules.
Late lodgement can attract Failure to Lodge penalties. One Commonwealth penalty unit is $364 from 1 July 2026.
Your firm should confirm each client’s operative date, then work backwards through records, preparation, review and approval.
What is a business activity statement (BAS)?
A Business Activity Statement (BAS) reports tax obligations such as GST, PAYG withholding and PAYG instalments. Depending on the client, it can also include other applicable tax labels.
The Australian Government Business Activity Statement overview recommends reconciling BAS figures to the underlying records, checking that transactions fall into the correct reporting period and completing only the sections that apply.
For your firm, that matters because a single BAS checklist will not suit every client. The preparation process should reflect the client’s registrations, reporting frequency and transaction profile.
Does every BAS client need a different preparation workflow?
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BAS due dates 2026–2027 at a glance
For planning purposes, separate the standard ATO deadline from an eligible online or registered-agent concession. The following table discusses the four FY2026–27 BAS lodgement quarters and shows when additional time may apply, helping your firm to schedule record collection, preparation, internal review and client approval before BAS lodgement.
| FY2026–27 quarterly BAS lodgement dates | |||
|---|---|---|---|
| Reporting period | Standard due date | Eligible registered-agent date | Eligible online self-lodgement |
| Q1: July–September 2026 | 28 October 2026 | 25 November 2026 | 11 November 2026 |
| Q2: October–December 2026 | 28 February 2027 | No standard agent extension | No extra concession |
| Q3: January–March 2027 | 28 April 2027 | 26 May 2027 | 12 May 2027 |
| Q4: April–June 2027 | 28 July 2027 | 25 August 2027* | 11 August 2027 |
*The Q4 registered-agent date remains subject to ATO confirmation.
Q2 needs extra attention. 28 February 2027 falls on a Sunday, and 1 March 2027 is a statewide public holiday in Western Australia. Under the ATO next-business-day rule, firms should verify the operative date shown on the statement rather than simply assuming 1 March.
When is the next BAS due?
As at 13 November 2026, the next standard monthly BAS deadline is 23 November 2026 for October 2026 because 21 November falls on a Saturday.
For eligible registered-agent clients, the Q1 quarterly concession date of 25 November 2026 may still apply.
The next standard Quarterly BAS period is Q2, covering October to December 2026. Your firm should confirm the statement-specific date before setting the final review timetable.
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Registered-agent concessions and BAS lodgement
A registered-agent concession is not a blanket extension across every BAS client.
Eligible electronic quarterly statements can receive later dates for Q1, Q3 and Q4. The December quarter is different because its standard February date already provides a longer lodgement period.
For your accounting practice management, record the operative date against each client rather than using one label such as “agent due”. That prevents your staff from assuming every client in the quarterly portfolio shares the same extension.
Monthly BAS due dates 2026–27
Monthly BAS is due on the 21st of the following month. When that date falls on a weekend or applicable public holiday, the next-business-day rule can change the effective date.
| Monthly BAS due dates FY2026–27 | ||
|---|---|---|
| BAS period | Standard due date | Weekend-adjusted date, if applicable |
| July 2026 | 21 August 2026 | 21 August 2026 |
| August 2026 | 21 September 2026 | 21 September 2026 |
| September 2026 | 21 October 2026 | 21 October 2026 |
| October 2026 | 21 November 2026 | 23 November 2026 |
| November 2026 | 21 December 2026 | 21 December 2026 |
| December 2026 | 21 January 2027 | 21 January 2027 |
| January 2027 | 21 February 2027 | 22 February 2027 |
| February 2027 | 21 March 2027 | 22 March 2027 |
| March 2027 | 21 April 2027 | 21 April 2027 |
| April 2027 | 21 May 2027 | 21 May 2027 |
| May 2027 | 21 June 2027 | 21 June 2027 |
| June 2027 | 21 July 2027 | 21 July 2027 |
Eligible December monthly statements lodged through a registered agent can receive different treatment, so use the date shown for that client.
Annual GST reporting follows another timetable. The due date aligns with the client’s income-tax return, while 28 February can apply where an income-tax return is not required.
Common BAS mistakes that create deadline pressure
The following are the common mistakes that consume the most review time often happen well before BAS lodgement:
- Treating every client as having the same date: Reporting cycles and concessions differ. Keep the actual due date against the client record.
- Waiting until review to chase documents: Missing invoices and bank statements should be identified during preparation, not when the senior accountant opens the file.
- Sending unresolved reconciliations forward: The reviewer at your firm should receive the difference, the work already performed and the supporting evidence, not an unexplained balance.
- Assuming an agent concession applies automatically: Confirm eligibility against the relevant statement before allocating internal deadlines.
- Confusing lodgement with payment: A BAS can be lodged while the liability remains unpaid. The two obligations should be tracked separately.
BAS due date checklist for accounting firms
The following checklist helps your firm catch missing records, reconciliation issues and deadline risks early, so BAS files reach review complete and on time.
- Confirm the correct reporting period and operative ATO date.
- Reconcile bank and credit-card accounts.
- Review GST-coded transactions.
- Check GST collected and GST credits.
- Reconcile payroll and PAYG withholding.
- Check PAYG instalments where applicable.
- Identify missing documents before review.
- Record unresolved items in one exception list.
- Complete internal review and client approval.
- Lodge by the applicable date.
- Arrange payment or a payment plan where required.
- Retain the supporting workpapers and records.
How should accounting firms plan BAS deadlines before the ATO due date?
The ATO date should be the final date in your workflow, not the first date staff think about the job.
For example, where a BAS is due on 28 April, your firm might require client records by 10 April, preparation by 17 April and manager review by 21 April.
Late clients should move to an exception register showing the missing information, responsible staff member and revised review date.
If routine preparation is repeatedly reaching senior staff, first define the tasks accounting firms can outsource.
What happens if BAS lodgement or payment is late?
Missing a BAS deadline can create two separate issues: late lodgement and late payment.
The ATO may apply a Failure to Lodge penalty when a required BAS is lodged late. From 1 July 2026, one Commonwealth penalty unit is $364. For a small entity, the base FTL calculation is one penalty unit for every 28 days, or part of a period, up to five units. The table below shows how late BAS penalties can increase over time.
| BAS failure to lodge penalty example for 2026–27 | ||
|---|---|---|
| Delay | Penalty units | Amount at $364 |
| 1–28 days | 1 | $364 |
| 29–56 days | 2 | $728 |
| 57–84 days | 3 | $1,092 |
| 85–112 days | 4 | $1,456 |
| 113+ days | 5 | $1,820 |
Different multipliers and remission rules can affect the final penalty.
Payment is separate from lodgement. An unpaid tax liability can attract a General Interest Charge, and GIC incurred on or after 1 July 2025 is not income-tax deductible.
If a client cannot pay, your firm should still manage lodgement separately rather than allowing a payment issue to create an avoidable late BAS problem.
If your firm is managing a large BAS portfolio, preventing that pressure comes down to moving routine preparation out of the review queue early enough.
Which BAS tasks can accounting firms delegate before lodgement?
The following table shows which BAS preparation tasks can move to an outsourced accountant and where your firm should step back in for review, judgement and approval.
| BAS preparation delegation framework | ||
|---|---|---|
| BAS task | Delegated preparation | Internal review |
| Client record check | Confirm agreed records have been received | Decide how unresolved information affects lodgement |
| Bookkeeping clean-up | Correct routine entries under documented procedures | Review material or unusual adjustments |
| Bank reconciliations | Complete reconciliations and identify unmatched items | Resolve unexplained differences |
| GST coding checks | Check recurring items against firm rules | Decide unusual GST treatment |
| Payroll and PAYG | Match payroll reports, ledger and withholding figures | Review unexplained variances |
| BAS workpapers | Prepare supporting schedules and draft figures | Complete technical review and approval |
| Exception register | List missing records and unresolved items | Decide what must be cleared before lodgement |
The handoff should stop when judgement begins. If an item cannot be resolved under documented instructions, it should be escalated with the supporting information rather than passed through as an unfinished file.
That makes the next question important: even when preparation is delegated, who remains responsible for the BAS?
Who remains responsible when BAS work is outsourced?
Outsourcing preparation does not transfer your firm’s professional responsibility.
TPB guidance states that when BAS services are performed by an unregistered third party, the work must remain under appropriate supervision and control of a registered practitioner. The registered practitioner remains responsible for the quality of work performed on their behalf.
Before files move, define:
- who prepares the work
- who reviews it
- what must be escalated
- who communicates technical decisions to the client
- who authorises lodgement
This keeps the outsourced preparation process connected to your firm’s existing review controls instead of creating a separate workflow.
Once those responsibilities are clear, the next check is how client information will be accessed and protected.
Pro tip
Keep one BAS exception register so preparers and reviewers see unresolved items before lodgement.
What should your firm check before BAS work is sent offshore?
BAS files can contain bank details, payroll information, invoices and personal information.
Before offshore access is provided, your firm should know:
- where client information will be accessed
- whether files can be stored or downloaded locally
- how user access is restricted
- whether MFA is required
- how access is removed when staff leave
- how activity is monitored
- how client consent and offshore disclosure are addressed
APP 8 can apply when personal information is disclosed to an overseas recipient. Your firm should therefore review privacy obligations alongside TPB confidentiality and outsourcing requirements before granting access.
The steps to onboard an outsourcing partner can help establish access, responsibilities, templates and review points before live BAS files move. With those controls in place, the final decision is how much BAS preparation your firm actually wants to delegate.
How AccountGlobal supports BAS preparation for 2026–27
AccountGlobal can support the preparation work that sits before your firm’s technical review.
Our highly experienced accountants can assist you with:
- bookkeeping clean-up
- bank and credit-card reconciliations
- GST coding checks against your documented procedures
- payroll and PAYG reconciliations
- supporting BAS workpapers
- missing-information lists
- draft BAS preparation
- clearing defined BAS backlogs
The right support model depends on how BAS work reaches your firm.
Project-based support can suit a defined backlog, a quarter with unusually high file volume or a batch of incomplete BAS files that needs preparation before review. Your firm can move a specific assignment without committing to an ongoing resource.
A dedicated virtual accountant is better suited to recurring monthly or quarterly BAS preparation across an established client portfolio. The same accountant can become familiar with your accounting software, workpaper templates, internal cut-offs, client requirements and escalation process.
Before increasing the scope of outsourced work, review the factors involved in choosing the right outsourced accounting partner.
Your registered practitioners continue to retain technical judgement, client advice, final review and authorised lodgement.
If upcoming BAS due dates for 2026–27 are already putting pressure on your review queue, contact us today to identify which reconciliations, workpapers and preparation tasks AccountGlobal can complete before files reach your reviewers.
FAQs about BAS due dates 2026–27
1. Which BAS tasks can we delegate without losing control of review and lodgement?
Delegate repeatable preparation such as reconciliations, routine GST coding checks, payroll matching, missing-information follow-up and BAS workpapers. Keep technical judgement, unusual GST treatment, client advice, final review and authorised lodgement with your registered practitioners under your existing review process.
2. How will the outsourced team handle unusual GST treatments, missing records and unresolved reconciliations?
Set escalation rules before work starts. At AccountGlobal, our specialised team flags unusual GST items, missing records and unexplained differences with supporting evidence, rather than guessing. Your senior accountant can then resolve the exception without reopening the file or repeating preparation.
3. What controls are in place to protect client data when BAS work is completed offshore?
Check where data is accessed, whether local downloads are restricted, how user permissions are controlled, whether MFA is required, how activity is monitored and how access is removed. Confirm offshore disclosure, confidentiality and privacy obligations before client files move.
4. How do we make sure outsourced BAS files reach our reviewers complete and ready for final review?
Use checklists, required workpapers, internal cut-offs and one exception register. Measure first-review quality, unresolved items and repeat corrections. The goal is for reviewers at your firm to receive reconciled files, supporting schedules, and clearly flagged exceptions instead of incomplete preparation needing rework.
Final takeaway on BAS due dates 2026–27
Knowing the BAS due dates 2026–27 is only the first step. The real planning work happens before those dates.
Confirm each client’s deadline, set earlier preparation and review cut-offs, identify missing information quickly and decide which repeatable BAS tasks can be delegated before they reach your reviewers.
That gives your firm more time for technical review, client decisions and lodgement instead of using the final days to finish reconciliations and workpapers.
Book a call with AccountGlobal to identify which BAS preparation tasks can move before your next reporting deadline while your firm retains review and lodgement control.
