Overview
This guide explains the key lodgment and payment dates advisers and taxpayers must observe, recent tax treatment changes that affect the cost of ATO debt, and practical steps to avoid failure-to-lodge penalties, interest charges, and scams. Implement these checks now to reduce client risk during the tax season.
Key dates you must know
• 31 October — Deadline for taxpayers who self-lodge their individual tax returns.
• 21 November — Usual payment due date for a tax bill arising from a self-lodged return.
• 15 May (registered-agent lodgments) — Standard lodgment due date for clients using a registered tax agent who engaged the agent before 31 October; later payment arrangements may apply under professional lodgment programs.
• BAS quarterly dates — Q1: 28 October; Q2: 28 February; Q3: 28 April; Q4: 28 July. Confirm client-specific BAS lodgment/quarterly instalment arrangements.
• Penalty clock — Failure-to-lodge penalties are assessed per 28-day period after the due date and escalate until the penalty cap is reached.
Recent change that increases the cost of ATO debt
• ATO interest on overdue tax is not tax-deductible from 1 July 2025.
This change increases the after-tax cost of holding ATO debt and makes early resolution or negotiated payment arrangements more financially sensible for many clients.
How penalties and interest operate
• Failure-to-lodge penalty: A monetary penalty is applied per 28 days late, with higher amounts for corporations and repeat offenders. Penalties continue until a statutory cap is reached.
• General interest charge (GIC): Interest accrues on unpaid liabilities from the day after the due date until the liability is paid. Interest compounds and may substantially increase the total debt.
• Interaction with voluntary disclosure: Timely voluntary disclosure can reduce penalties where an error is found and corrected proactively; it does not automatically remove interest but may influence penalty remissions.
Practical pre-lodgment checklist to avoid penalties and reviews
1. Wait for finalised prefill
• Confirm STP and private health insurance prefill is finalised before lodging individual returns. Early lodgement often leads to amendments and potential review.
2. Reconcile all income sources
• Compare client records to ATO prefill for PAYG, dividends, interest, rental, gig platform income, and crypto disposals. Resolve discrepancies before lodge.
3. Confirm HECS/HELP and child support positions
• Verify current year balances and repayment obligations so the assessed liability is accurate at lodgment.
4. Document reasonable basis for deductions
• Keep contemporaneous evidence and a short audit note explaining any complex apportionment or significant claims.
5. Use registered-agent lodgment where appropriate
• For complex or late clients, engage a registered agent to access extended lodgment schedules and professional safeguards.
6. Model payment options
• For clients facing larger bills, present ATO payment plan options and illustrate after-tax cost given non-deductibility of interest.
7. Prepare an amendments workflow
• Have a standard process for assessing, approving, and lodging amended returns, with documented client authorisation and a timeline for follow-up.