Amending an individual income tax return in Australia

Correct an error by requesting an amendment to the assessment for the affected income year. Wait for the original return to be processed, establish the applicable time limit, and reconcile every proposed change to supporting records. This guide covers individuals and sole traders. Sources checked on 8 September 2026.

Establish the amendment period

Most individuals have a two-year amendment period. Sole traders generally had two years for 2023–24 and earlier income years. For 2024–25 and later years, sole traders can generally request amendments within four years. Record the income year and the date the ATO gave notice of the original assessment. The period does not run from the end of the income year or the day the return was lodged. ATO: time limits on amendments.

The four-year extension for small and medium businesses is a taxpayer-requested amendment mechanism. Item 3A of subsection 170(1) requires an application in the approved form within four years, after the ordinary two-year period has ended. It applies to assessments issued after 1 January 2025 for income years starting on or after 1 July 2024. It does not give the ATO an unrestricted four-year review period for every sole trader.

Some individuals fall outside the ordinary two-year category, including through business, partnership, trust or avoidance circumstances. Fraud or evasion and review or appeal decisions have separate rules. An amended assessment does not restart the amendment period for the whole return: sections 170(2)–(4) restrict further amendments and allow particular matters to be revisited in specified circumstances. For an assessment near its deadline, have the statutory period and any extension checked before lodging. ITAA 1936, section 170.

Prepare the correction

Keep the original return, original notice of assessment, every amendment and ATO decision, and the records supporting the correction. Prepare one reconciliation for each affected label:

Item	Record
Existing amount	Amount in the latest processed assessment or return data
Correct amount	Recalculated total for the same income year
Difference	Increase or decrease, with the sign stated
Evidence	Invoice, statement, calculation or other supporting record
Explanation	What was wrong and why the replacement amount is correct

Recalculate related items, such as taxable income, offsets, capital losses, Medicare levy and study loan repayment income where affected. A deduction added to a return does not necessarily produce a refund equal to the deduction multiplied by one marginal rate. Other thresholds, offsets and liabilities can change.

Separate a favourable correction from a tax shortfall. An understated liability or overstated entitlement may create a shortfall; a correction that reduces tax is not automatically a shortfall. Do not invent missing expenses, dates or valuations. Mark incomplete items for resolution before submission.

Lodge through an available channel

The ATO accepts individual amendment requests through ATO online services, a registered tax agent, the relevant paper amendment form, or a letter containing the required information. In myGov linked to the ATO, use Manage tax returns, then Amend beside the relevant income year. Enter the correct totals for the affected labels, rather than replacing a total with only the adjustment.

Retain the submitted request and acknowledgement. A paper request must be signed by the taxpayer. Follow the ATO's current instructions for required identifiers and supporting documents, and provide them through the ATO or authorised agent's secure channel. The ATO does not charge a fee for requesting an amendment. Processing times are estimates, not a guarantee that a request will be completed before a deadline. ATO: how to request an amendment.

If the amendment period has expired, consider an objection and, where necessary, an extension of time to object. An amendment request and an objection are different processes. Use the objection process where disputing an ATO decision requires it; do not assume another amendment request preserves review rights. ATO: amendment time limits and objections.

Check interest, penalties and the result

Additional tax can carry interest. A false or misleading statement that produces a shortfall may also attract a penalty. The ordinary base penalty is 25 per cent of the shortfall for failure to take reasonable care, 50 per cent for recklessness and 75 per cent for intentional disregard. These are starting points, subject to the applicable provisions, increases, reductions and remission. An honest error is not proof of recklessness, and using an agent does not by itself establish reasonable care.

Voluntary disclosure can reduce penalties, but does not guarantee that tax, interest or penalties disappear. Check the timing and content requirements. Obtain legal advice where fraud, evasion or privilege is in issue. ATO: false or misleading statement penalties.

When the amended assessment arrives, compare it with the submitted reconciliation. Check the tax difference, interest, penalties, credits, payment date and any effect on later returns. Retain the assessment and the evidence supporting each corrected figure.

Contributed by Ryan Duguid.