How to change your tax return after you've lodged it

If you think you made a mistake on your income tax return after filing it, it is vital that you contact the ATO immediately in order to amend it.

You can ask for an amendment by letter, by using the online form on the ATO website, or you can report the amendment through myGov. An online amendment takes about 20 days to process.

In addition, a tax agent can amend your tax return and lodge it for you.

How long you have to lodge an amendment

The deadline for amendments is generally two years from the day after your original notice of assessment is sent to you.

For example, say you lodged your original tax return on October 25, 2022, and received a notice of assessment on November 3, 2022; the amendment period begins on November 4, 2022, and ends on November 3, 2024.

Beyond that date, amendments to your assessment are not usually possible, however, you can lodge an objection instead.

While the time limit for objections and amendments is the same - two years - the ATO does allow you to request an extension of time to lodge an objection in some circumstances.

Examples of when a late objection would be allowed include:

• You were too ill to lodge an earlier objection
• You were overseas and did not return until the time limit had expired
• The taxation decision was sent to the wrong address or there were problems with the mail service
• You thought that there was no point objecting but a court decision, a change in legislation or a public ruling by the ATO delivered shortly after the time limit expired made the objection reasonable or alternatively you based your decision not to object on faulty information provided by the ATO

Why you might need to request an amendment

There are a number of reasons why you might seek to amend an already lodged return, including:

1. Answering (or not answering) a question on the tax return by mistake
2. Forgetting to include an item of income or a capital gain
3. Forgetting to claim an offset or a deduction
4. Repaying income you were overpaid after filing your tax return
5. You become aware that you have treated an item of income, a deduction or an offset incorrectly

If the amendment reduces your tax liability, you are entitled to a tax refund unless there are other tax debts you need to pay.

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