ATO late lodgement penalty: up to $364 per 28 days, capped at $1,820 per document · interest 11.43% p.a. compounding daily · See how to remit them →
Amendment, objection or new return: which one do you need?
| Situation | The right fix |
|---|---|
| Made a mistake, or forgot income or a deduction, on a lodged return | Amendment (this guide) |
| Disagree with an ATO decision, or your amendment window has closed | Objection, a formal review with different time limits |
| Never lodged the year at all | Not an amendment, lodge the overdue return |
| ATO issued a default assessment for a year you didn't lodge | Lodge the real return plus an objection |
Never lodged at all? Start with the overdue tax returns guide. Hit with an estimate? See how default assessments work.
The time limits, and where people get burned
The amendment period runs from the date of your notice of assessment, not from lodgment day and not from 30 June:
| Taxpayer | Amendment period |
|---|---|
| Most individuals and small businesses | 2 years |
| Individuals with complex affairs (for example trust distributions outside prescribed types) and larger entities | 4 years |
| Fraud or evasion involved | No limit, the ATO can go back indefinitely |
The window is fixed from the original notice, so amending doesn't reset it. Miss it and the amendment route closes, but an objection can still be lodged, and you can ask for an extension of time to object, which the ATO grants for good reasons. For old refunds you've only just discovered, objection with an extension is the pathway. It's harder than amending, so check your dates today.
How to amend: three ways
Amending a lodged tax return
myTax, fastest for most people
myGov, then ATO online services, then Manage tax returns, select the year and choose Amend. Your lodged figures pre-load, so change only what's wrong, add a reason and submit. Processing takes up to 20 business days and is usually faster.
Through a tax agent
Agents amend via their portal in minutes and, more valuably, sanity-check whether your mistake is actually claimable, whether the amendment carries review risk, and whether other labels need fixing at the same time. If the error came from your agent's work, say so, because it matters for interest remission.
Paper form
The request for amendment of income tax return form, by mail, takes up to 50 business days. Only sensible when online access is impossible.
What happens after you amend
If the ATO owes you: an amended notice of assessment issues and the refund pays out like a normal return, plus interest on the overpaid amount where the original overpayment was the ATO's doing.
If you owe the ATO: you'll get an amended assessment with the shortfall, plus shortfall interest charge (SIC), a lower rate than standard GIC, from the original due date to the amendment. Here's the part that surprises people pleasantly: voluntarily amending before the ATO contacts you cuts or eliminates shortfall penalties. Penalties for false or misleading statements (25% to 75% of the shortfall) are typically reduced by 80% for voluntary disclosure made before you're notified of an audit, often to nothing for genuine mistakes. Waiting for data-matching to catch it costs the full freight. How SIC and GIC differ.
The 5 most common amendments, and what to enter
- Forgot interest or dividend income: add at labels 10 and 11. This is the number-one data-matching catch, so amend before they write to you.
- Missed a deduction: work expenses at D1 to D10. Keep the evidence, because amendments claiming new deductions are reviewed more often.
- Forgot a capital gain: label 18, and calculate it properly first with our CGT calculator.
- Wrong private health details: fix the policy and rebate labels, usually a small swing either way.
- Employer issued a revised income statement: re-sync income labels to the final reported figures.
Need the capital gain worked out? Use the capital gains tax calculator before you amend.
Amendment periods and penalty concessions checked July 2026.
Frequently asked questions
How do I amend my tax return with the ATO?
How far back can I amend a tax return?
Will I be penalised for amending my tax return?
How long does an amended tax return take?
Can I amend a return the ATO is reviewing?
How many times can I amend the same return?
General information only - not personal tax, financial or legal advice. Consider your own circumstances or speak to a registered tax agent. Remission of penalties or interest and payment plans are decisions of the ATO and outcomes can't be guaranteed.