BAS due dates 2026–27: Monthly, quarterly, and annual deadlines

The BAS due dates for the 2026–27 financial year vary depending on your GST reporting cycle. Monthly BAS is generally due on the 21st of the following month, while quarterly BAS is due on 28 October 2026, 28 February 2027, 28 April 2027, and 28 July 2027.

Eligible businesses reporting annually have different lodgement deadlines. Missing a BAS due date can result in Failure to Lodge (FTL) penalties, General Interest Charges (GIC), and unnecessary cash flow pressure. This blog post explains every BAS due date for 2026–27, which deadline each applies to, available tax agent extensions, penalties for late lodgement and practical tips to help your business remain compliant.

What are the BAS due dates?

BAS due dates are the deadlines set by the Australian Taxation Office (ATO) for lodging your Business Activity Statement and paying any amount reported in it. A BAS may include GST, PAYG withholding, PAYG instalments and other business tax obligations.

Most Australian businesses registered for GST must lodge a BAS. Monthly reporting is generally required for larger businesses, while most small and medium-sized businesses lodge quarterly. Eligible businesses may be able to lodge annually.

If a BAS due date falls on a weekend or public holiday, the deadline usually moves to the next business day. Lodging and paying on time helps businesses avoid penalties, interest charges and cash flow pressure.

Businesses that lodge through a registered BAS or tax agent may receive additional time for certain quarterly lodgements under the ATO’s lodgement concession program. However, extensions depend on eligibility and do not generally apply to monthly BAS statements.

BAS due dates 2026-27: Lodgement & payment deadlines

The BAS due dates for the 2026–27 financial year depend on your GST reporting cycle. Use the tables below to find your monthly, quarterly or annual lodgement deadline, including the extra concession (extension) if you lodge through a registered BAS/tax agent and electronically under the ATO’s BAS Agent Lodgment Program:

What happens if you miss a BAS due date?

Here are the main consequences you need to be aware of If you miss a BAS due date 2026–27.

Failure to Lodge (FTL) penalty:

The ATO applies a Failure to Lodge (FTL) penalty when your BAS is lodged after the due date. For the 2026–27 financial year, eligible small businesses may be charged $364 for every 28 days (or part thereof) that the BAS remains overdue, up to a maximum of five penalty units ($1,820).

Medium and large entities are charged at higher multiples, and global entities face significantly larger penalties. Because the process is automated, repeated late lodgements reduce your chances of penalty remission. For more information, you can visit the ATO Failure to Lodge penalties page.

General interest charge (GIC):

The ATO also applies a General Interest Charge to unpaid BAS amounts from the day after the payment due date until the debt is paid in full. GIC is calculated daily on a compounding basis, with the rate reviewed quarterly. From 1 July 2025, GIC is no longer tax-deductible. In limited circumstances, the ATO may remit GIC if your business experienced genuine extenuating circumstances that prevented payment on time.

Cash flow strain

When GST refunds are withheld, your working capital is reduced straight away. Without access to these funds, it becomes difficult to cover wages, supplier payments, and regular bills.

Many business owners are then forced to borrow, delay obligations, or dip into personal savings to keep operations running. Even short delays in refunds can create disruption, while ongoing delays may place long-term stability at risk.

Compliance and audit risk:

Your lodgement behaviour is tracked by the ATO, and repeated delays weaken your compliance record. Once your record is damaged, the risk of an audit or review rises sharply. You may also lose the extra time offered under BAS agent extensions. Over time, this creates a cycle of closer monitoring and stricter treatment.

Business reputation and finance access:

Banks, lenders, and suppliers often request BAS records as proof of financial reliability. Consistent delays raise red flags that can limit access to credit and reduce negotiating power. A poor record also damages trust with partners and stakeholders. Over time, this weakens your reputation and restricts your business growth opportunities.

Best practices to prepare for BAS due dates

Avoiding penalties is much easier when you treat BAS preparation as a structured process rather than a rushed task. Here are tips on how to prepare BAS effectively:

Confirm your reporting cycle early:

Check whether you report monthly, quarterly, or annually, and make sure this matches what the ATO has on record. Align your accounting software settings with the same cycle. Share the timing with your bookkeeper and payroll so everyone works to one calendar. Create a simple year planner that lists each period’s cut-off date.

Get your bookkeeping in order:

Record sales, purchases, and expenses promptly and attach source documents to each transaction. Use detailed descriptions so future reviews make sense at a glance, and always keep business and personal payments separate to avoid messy coding. By maintaining accurate bookkeeping for BAS preparation throughout the year, you will make the activity statement process far less stressful.

Reconcile bank and clearing accounts:

Reconcile bank feeds, merchant accounts, and payroll clearing accounts at least monthly. Investigate any unmatched items and fix them before the period closes. Confirm suspense accounts are cleared to the right codes. A reconciled ledger is the foundation of accurate BAS figures.

Track GST, PAYG withholding, and PAYG instalments:

Check that GST on sales and purchases is recorded correctly and that GST-free or input-taxed items are not overstated. Always make sure PAYG withholding reconciles with the general ledger. Many businesses rely on professional payroll services providers to ensure payroll reports for PAYG withholding align seamlessly with BAS preparation, giving confidence that figures are accurate and fully compliant.

Use accounting software features well:

Tools like Xero accounting software or QuickBooks accounting software can automate bank feeds, rule-based coding, and document attachments. Turn on user roles and approvals so transactions are reviewed before posting. Run GST summary and exception reports to catch errors early. Set up due date reminders inside the software.

Build a pre-lodgement checklist:

Include reconciliations, GST exception review, payroll reports, PAYG summaries, and a scan for unusual balances. Tick off each step the same way every period. A short checklist prevents small mistakes from becoming penalties. Save the checklist with the period’s working papers.

Monitor cash flow for upcoming BAS payments:

Forecast the GST and PAYG amounts due so you are not caught short near the BAS deadline. Put aside funds in a tax holding account as the period progresses. If cash is tight, plan early and speak with your adviser about options before the due date arrives.

Set calendar alerts and team reminders:

Add all BAS due dates to a shared calendar and include any agent concessions you receive. Schedule internal cut-offs for coding, reconciliations, and reviews. Remind approvers to sign off on time. Clear internal timelines make the external deadline easy.

Prepare early and close the period:

Aim to finalise coding and reconciliations a week before the BAS lodgement due date. Lock the period in your software once the statement is ready, so no late edits slip in. Early preparation gives you room to fix issues without stress.

Fix errors quickly and document changes:

If you spot an error after lodgement, prepare a clear adjustment in the next BAS or request an amendment as appropriate. Keep notes that explain the issue, the correction, and the supporting documents. Good documentation protects you if questions arise later.

Keep source documentation:

Store tax invoices, receipts, credit notes, payroll reports, and bank statements in one secure location. Use consistent file names and period folders. Good records make BAS preparation easier and support your position during reviews.

Stay informed on ATO updates:

Rules change, thresholds move, and lodgement concessions can be updated. Check ATO guidance each quarter or subscribe to updates. Update your checklist when something changes so your process stays current.

Work with a registered BAS agent for accuracy and extra time:

A registered agent reviews your figures, helps prevent mistakes, and can access extended lodgement time under the ATO agent program when conditions are met.

Create a brief period file for audit trail:

Save the BAS PDF, GST reports, payroll summaries, bank recs, and your signed checklist together. A tidy period file means questions are easy to answer, and future periods are faster to prepare.

Partner with CleanSlate for stress-free BAS lodgement

Managing BAS lodgements shouldn’t take up valuable hours you could spend running your business. At CleanSlate, we provide end-to-end BAS support that keeps you compliant and gives you peace of mind. Our team ensures your reports are accurate, on time, and aligned with ATO requirements no last-minute stress, no unnecessary penalties.

Here’s what we bring to the table:

• Accurate bookkeeping and reconciliations – all sales, purchases, and payroll figures are properly coded and checked before lodgement.
• On-time lodgements every cycle – whether you report monthly, quarterly, or annually, we make sure deadlines are never missed.
• Cash flow planning support – we help you forecast GST and PAYG so you can set aside funds and avoid sudden shortfalls.
• ATO compliance confidence – your BAS is reviewed by professionals who know the latest rules and reporting concessions.
• Extra time with agent concessions – lodging through CleanSlate gives you access to extended deadlines when available.

By working with us, you gain more than just compliance. You gain the freedom to focus on your business growth, knowing your BAS obligations are being handled with precision and care. Get in touch with us today and take the stress out of BAS lodgements.