BAS Due Dates Australia: A Practical Guide for Accounting Firms
A practical guide to BAS due dates in Australia for tax agents and accounting firms, including lodgement deadlines, client reminders and workflow planning.
This guide is written for Australian tax agents, BAS agents and accounting firms managing GST clients. It explains how the obligation fits into Australian public practice, how firms can plan lodgement deadlines before they become urgent, and how client reminders, workflow ownership and practice management routines can reduce compliance risk.
Key dates and timing considerations
Due dates are only useful when the firm turns them into a working system. Australian accounting firms need to know the statutory or ATO lodgement deadline, but they also need earlier internal workflow dates for record collection, preparation, manager review, partner review, client approval and final lodgement.
- Quarter 1 (July–September): 28 October.
- Quarter 2 (October–December): 28 February; this date already includes the ATO's one-month extension.
- Quarter 3 (January–March): 28 April.
- Quarter 4 (April–June): 28 July.
- Eligible online quarterly lodgers may receive an extra two weeks for quarters 1, 3 and 4. Registered tax or BAS agent dates can differ and should be checked on the issued activity statement or in Online services for agents.
- Monthly BAS is generally due on the 21st day of the following month. Eligible electronic December monthly BAS lodgers may have a 21 February due date.
- Annual GST is generally due 31 October, or 28 February if no income tax return is required; agent dates can differ.
How to operationalise this inside an accounting firm
The most effective firms treat this topic as part of a wider compliance operating rhythm, not as an isolated date in a diary. A partner, director or manager should be able to open one view and see which clients are affected, which due dates are coming up, which reminders have been sent, which work is waiting on the client and which lodgements are at risk. That visibility is what turns a tax calendar into a practice management tool.
For public practice teams, the first step is to define ownership. Every client should have a responsible manager or staff member, and every recurring obligation should have a clear workflow path. That path normally includes information requested, information received, preparation started, manager review, partner review, client approval and lodged. Smaller firms may use fewer stages, but the principle is the same: the firm needs a shared language for progress.
Client communication
Client reminders should be specific, early and consistent. A useful reminder explains what the firm needs, when it is needed, what the client should do next and why the timing matters for ATO compliance or the relevant lodgement deadline.
Manager visibility
Managers need more than a list of dates. They need to know which clients have not responded, which jobs are unassigned, which obligations are approaching review and where workflow capacity is becoming tight across the team.
This is especially important when a firm is moving away from a spreadsheet. Spreadsheets can record due dates, but they rarely create reliable accountability. They do not automatically show whether a client reminder was sent, whether a manager changed, whether an email bounced, or whether a lodgement is still waiting for approval. A structured compliance workflow gives the team a better way to manage recurring deadlines without relying on memory or inbox archaeology.
What BAS due dates mean in practice
A Business Activity Statement, usually called a BAS, is one of the most common recurring compliance obligations handled by Australian accounting firms. BAS reporting can include GST, PAYG withholding, PAYG instalments and other labels depending on the client. Because BAS work recurs monthly or quarterly, it is a perfect example of why firms need a dependable tax calendar rather than an end-of-month scramble.
The ATO's standard quarterly dates are 28 October, 28 February, 28 April and 28 July. If a due date falls on a weekend or public holiday, lodgment and payment move to the next business day. Eligible online lodgers may receive two extra weeks for quarters 1, 3 and 4, while registered-agent program dates depend on eligibility and are displayed against the client's activity statement.
The ATO due date is only the final compliance date. A well-run public practice works backwards from that date. The firm needs time to request source records, chase missing bank statements, prepare bookkeeping, review GST coding, ask client questions, obtain approval and lodge through the correct channel.
For a public practice, the operational risk is rarely the date itself. The risk is that no-one owns the follow-up, the client reminder is sent too late, the manager cannot see what is stuck, or the team is using a spreadsheet that is no longer trusted. TaxCalendar is designed to connect due dates, client reminders, workflow ownership and compliance visibility in one place.
BAS obligation settings
TaxCalendar's obligation settings showing the firm's Quarterly BAS due date configured directly against the obligation type.
Staged reminder queue
TaxCalendar's reminder queue showing a staged Quarterly BAS reminder scheduled 30 days before the due date, alongside other obligation types.
How firms should plan BAS reminders
A practical BAS reminder sequence usually starts well before the ATO lodgement deadline. Many firms use reminders around 30, 14, 7 and 2 days before the due date, then a final due-date reminder. The exact schedule should depend on the client's bookkeeping habits, the firm review process and whether the client usually provides information early or late.
For tax agents, it is useful to separate client-facing reminders from internal workflow dates. Client reminders ask for records and approvals. Workflow dates tell the team when the BAS should be prepared and reviewed. Treating both as the same date creates pressure and makes it hard for managers to see which jobs are actually at risk.
Common BAS workflow mistakes
The most common mistake is relying on a spreadsheet that tracks the ATO due date but not the work required before lodgement. A second mistake is assuming the client reminder has been sent because it was on someone's list. A third mistake is giving partners visibility only after the deadline is close.
A better approach is to track the obligation, manager, client status, reminder schedule and lodgement status together. That gives the firm one view of what is due, what has been requested, what is lodged and what still needs attention.
Recommended reminder and workflow cadence
A strong compliance process separates client communication from internal work allocation. Tax agents can use client reminders at 30, 14, 7, 2 and 0 days before the due date, while managers use earlier workflow dates to check whether records have arrived, preparation has started and review is on track.
This matters because lodgement deadlines are rarely missed for one dramatic reason. They are missed because small items stay hidden: a missing email address, an unassigned manager, a client who has not approved the work, or an obligation sitting in a spreadsheet that only one person trusts. TaxCalendar is built to make those issues visible before they become deadline pressure.
Where TaxCalendar fits
TaxCalendar helps Australian accounting firms turn compliance dates into a visible workflow. Firms can track clients, obligations, due dates, manager ownership, reminder status and lodged status in one place. That gives public practice teams a practical operating layer for BAS, IAS, ATO lodgement calendars, annual returns, client reminders and recurring practice management routines.
Related questions
When are quarterly BAS due dates in Australia?
The ATO's standard quarterly BAS dates are 28 October for quarter 1, 28 February for quarter 2, 28 April for quarter 3 and 28 July for quarter 4. Weekend and public-holiday rules, eligible online concessions and registered-agent program dates can change the actual date shown for a client.
Does lodging a quarterly BAS online give extra time?
Eligible online lodgers may receive an extra two weeks for quarters 1, 3 and 4. Quarter 2 does not receive that additional concession because its 28 February deadline already includes an extension. Always use the date displayed on the activity statement.
Should BAS reminders use the ATO due date or an internal workflow date?
Use both. The ATO date is the compliance deadline, while internal workflow dates help the firm prepare, review and lodge before the deadline becomes urgent.
Can TaxCalendar help with BAS client reminders?
Yes. TaxCalendar helps firms track BAS obligations, schedule client reminders and monitor workflow status across the practice.
How do I track BAS lodgement deadlines across a whole client base?
Record each client's BAS due date against a shared obligation record rather than a personal calendar or spreadsheet, then attach a staged reminder schedule and a workflow status so managers can see what is due, what has been requested from the client and what is still outstanding at a glance.
Sources
Facts and figures in this guide are drawn from the following official sources. Rates and thresholds are indexed periodically, so always confirm current amounts before quoting them to a client.