What Happens If You Don't Lodge a Tax Return in Australia?

If you miss the tax return deadline in Australia and do not lodge, the ATO can impose a Failure to Lodge (FTL) penalty, charge interest on any tax owing, and ultimately issue a default assessment based on its own estimate of your income. The longer you wait, the more the penalties and interest accumulate — but voluntary action at any point reduces the exposure.

The Failure to Lodge (FTL) Penalty

The ATO imposes a Failure to Lodge penalty when a tax return is not lodged by the due date. The penalty applies to:

• Individual tax returns
• Business Activity Statements
• Any other document with a legal lodgement deadline

FTL penalty amount:

The $330 per period amount is based on one penalty unit ($330 in FY2025–26). For large companies, the penalty unit multiplier is much higher — up to 500 penalty units per period.

Important: The FTL penalty applies even if you would receive a refund. It is a penalty for not lodging, not for not paying.

The ATO’s Process for Non-Lodgers

The ATO does not immediately impose FTL penalties the day after the deadline. Its typical process:

1. Pre-lodgement reminder — the ATO may send a letter or SMS reminder before the deadline
2. Post-deadline follow-up — the ATO sends a “lodge now” notice if the return is not received
3. Failure to Lodge penalty notice — a formal penalty assessment is issued
4. Default assessment — if still no response, the ATO may issue a default assessment (an estimate of your tax liability based on available data, such as employer reporting, bank data, and prior year returns)
5. Debt collection — unresolved assessed debt may be referred to debt collection activities including credit reporting and legal proceedings

The ATO has significant data-matching capabilities — it receives information from employers, banks, share registries, Centrelink, and other agencies. It generally knows you have assessable income even without your return.

General Interest Charge on Unpaid Tax

If your return, when eventually lodged, shows a tax liability and the due date for payment has passed, the General Interest Charge (GIC) applies from the date the payment was due. The GIC is currently around 11–12% per year, compounding daily.

This means delaying lodgement for multiple years can result in:

• The original tax debt
• FTL penalties (up to $1,650 per year of return)
• GIC accumulating daily on the tax debt

ATO’s Approach to Voluntary Disclosure

The ATO applies a voluntary disclosure policy — if you come forward and lodge before the ATO initiates contact about a specific failure, the FTL penalty may be partially or fully remitted. The ATO’s stated position is that it prefers voluntary compliance over enforcement.

Key points:

• Lodging late is better than not lodging at all
• Engaging a tax agent to manage a multi-year catch-up is often the most effective approach
• The ATO can set up payment plans for people who cannot pay their debt immediately
• In genuine financial hardship cases, interest (and sometimes penalties) can be partially waived on application

What to Do If You Have Not Lodged

1. Work out which years are outstanding — check your myGov/ATO account to see which years show as “Not lodged”
2. Gather records — employer income statements, bank statements, receipts
3. Lodge via myTax for recent years (returns can usually be lodged via myTax for the last two years)
4. Engage a tax agent for older returns — they can access prior year return forms and manage ATO communication
5. Contact the ATO proactively if you have significant debt — a payment plan prevents escalation

Frequently Asked Questions

What if I was not required to lodge but the ATO sends me a notice anyway? Use the ATO’s “non-lodgement advice” form to notify the ATO you were not required to lodge. This clears the record without incurring penalties. Reasons for non-lodgement include income below the threshold with no tax withheld.

Can the ATO take legal action for not lodging? Yes. Non-lodgement is an offence under the taxation acts. Prosecution is rare and typically reserved for deliberate, repeated non-compliance, but the legal framework exists and the ATO does pursue serious cases.

What happens to the FTL penalty if I lodge late but am owed a refund? The ATO has discretion to remit FTL penalties, and often does so when there is no tax owing and the taxpayer has a good compliance history. However, this is not guaranteed — the best approach is to lodge on time.

How far back can the ATO go in issuing a default assessment? The standard amendment period is generally two years for individuals (four years for businesses). The ATO can go beyond this for fraud or evasion. For most people, the primary concern is the most recent few years of non-lodgement.

This article provides general tax information. If you have outstanding lodgement obligations, speaking with a registered tax agent is strongly recommended. Find one through the Tax Practitioners Board register.