If you made an error or omitted income or deductions from a tax return you have already lodged, you can amend it. Most individuals can amend recent returns via myTax in myGov. The ATO allows amendments within two years of the original assessment date for individuals (four years for small businesses).
When Should You Amend Your Return?
Common reasons to amend include:
- You forgot to declare income (bank interest, a dividend, rental income, crypto)
- You claimed a deduction you were not entitled to
- You missed a legitimate deduction
- You entered the wrong figures (income, bank account details)
- You received an amended income statement from your employer after lodging
If the error resulted in you paying less tax than you should have, it is important to amend voluntarily rather than wait — the ATO is more likely to remit penalties and interest for voluntary disclosure.
Time Limit for Amendments
| Taxpayer type | Amendment period |
|---|---|
| Individuals and small businesses | 2 years from the date of the original assessment |
| Other entities (companies, trusts) | 4 years from the date of the original assessment |
| Fraud or evasion | No time limit |
The original assessment date is shown on your Notice of Assessment and is generally issued a few days after your return is processed.
Method 1 — Amend via myTax (Recommended)
For returns lodged in the last 1–2 years, myTax allows you to amend online:
- Log in to myGov and open ATO online services
- Go to Tax → Returns
- Select the relevant year
- Select Amend (this option appears for years within the amendment window)
- Make the corrections — only change what needs changing
- Review the updated tax summary
- Submit the amendment
The ATO will process the amendment and issue a new Notice of Assessment. If additional tax is owing, it will become payable (interest may apply from the original due date). If you over-paid, a refund will be issued.
Method 2 — Amend Through a Tax Agent
If the return was originally lodged through a tax agent, contact them to lodge the amendment. Agents can submit amendments through the ATO’s business software systems (ATO online services for agents). This is often the best approach for complex amendments.
Method 3 — Paper Amendment Request
If your return is older than what myTax supports online, you can write to the ATO requesting an amendment. Your letter should include:
- Your full name and TFN
- The financial year being amended
- The specific items being corrected
- The correct figures and an explanation
- Supporting documentation if relevant
Send to the ATO’s postal address for your state (available at ato.gov.au). Paper amendments take longer to process than electronic ones.
What Happens After You Amend
The ATO will:
- Review the amendment
- Issue a new Notice of Assessment reflecting the correct tax position
- Either: issue a refund (if you overpaid), or show an amount owing (if you underpaid)
If an underpayment resulted from an error, the ATO may impose:
- General Interest Charge (GIC) on the additional tax owing from the original due date
- A false and misleading statement penalty in serious cases, though these are rarely imposed for honest mistakes
Voluntary amendments generally attract more lenient treatment than corrections initiated by the ATO.
Frequently Asked Questions
Can I amend a return lodged by a tax agent myself? Yes. If it is within the amendment window, you can amend via myTax regardless of how the original return was lodged. However, if the return is complex, it is better to work with the tax agent.
What if the amendment reduces the tax I owe — do I get a refund? Yes. If the amendment results in a lower tax liability than you paid, the ATO will refund the difference.
Does the ATO charge penalties for amending? For honest mistakes corrected voluntarily, the ATO does not typically impose penalties beyond the General Interest Charge on any additional tax owing. Intentional omissions treated as fraud or evasion are treated more seriously.
What if I realise a prior-year deduction was wrong but I am outside the two-year window? The ATO has a process for requesting amendments outside the standard window in limited circumstances. Contact the ATO or a tax agent to discuss your specific situation.
How long does an amendment take? Electronic amendments via myTax typically take 2–4 weeks to process. Paper amendments can take longer — up to 8–10 weeks.
This article provides general tax information. For advice tailored to your situation, speak with a registered tax agent. Find one through the Tax Practitioners Board register.