Finder makes money from featured partners, but editorial opinions are our own.

How to amend your tax return

If you find a mistake after your tax return forms have been lodged and assessed, there's an easy way to ask the ATO to fix it.

Although you likely checked and then double checked your tax forms before lodging them with the ATO, there are times when an error is noted afterwards. This may be your error, a tax preparer’s error, or a mistake made by the ATO. If you do find a mistake, you have two years from the time your tax forms were assessed to bring it to the attention of the ATO. This is done by requesting an amendment either for a mistake or an omission.

How to request an amendment on a tax return

You can use the form provided by the ATO to request an amendment. Make sure that it is filled out in its entirety and signed by you before you send it to the ATO office. A registered tax agent can also make the request on your behalf, provided that they have your expressed permission to do so. It is also important to note that even if you used myGov to lodge your tax return with the ATO the amendment request must be done in writing.

If you decide not to use the form provided by the ATO you will have to supply them with a detailed letter that includes all of the following information:

  • Your tax file number (TFN)
  • Your full name as it appears on your tax records
  • Your postal address
  • A daytime phone number where you can be reached if additional information is required
  • The tax year for the tax return that you are requesting be amended
  • The item number on the tax form that the amendment pertains to and a detailed description of the change
  • The exact monetary amount of the change, whether it be in your income or deductions
  • The exact amount of tax offsets that need to be increased or decreased
  • If available, the claim type code
  • An explanation of how the mistake was made, and a reason for the change
  • A declaration signed and dated by you that states:
    • I declare that all the information I have given in this letter, including any attachments, is true and correct
    • I have the necessary receipts and/or records to support my claims for amendment

Do I need to tell the ATO I made a mistake?

The short answer is, yes. If you voluntarily disclose an error made on your tax return to the ATO and it results in you owing more money, you will receive concessional treatment and not have to pay any penalty or interest. If the mistake is in your favour, you could be entitled to an additional refund which will be paid to you. If you do not disclose a mistake that was made and the ATO discovers it, you could face additional financial charges.

What are the time limits on amendment requests?

It is important that you amend a tax return as quickly as possible after realising a mistake has been made in order to avoid penalties. You can request an amendment by using the form on the ATO website. Once filled out you can print it and either send it by fax or mail to the ATO.

For individual taxpayers and small businesses, the time limit to request an amendment on your Australian tax form is two years following the date of assessment. After that time period you would have to lodge an objection, which allows for extensions under certain circumstances.

How does the ATO process my amendment?

Just as the ATO accepts your return at face value in most cases, it also accepts your amendment request. How long before the adjustment is made will depend on the nature of the error. If you made a mistake in reporting your income or deduction, it could take up to 50 days to process or 20 if sent to the ATO by a tax agent. If the mistake was made by the ATO then the processing time is 14 days.

There may be situations where additional information is needed. In those cases the ATO will ask for that information within 14 days of receiving the request. If they are still unable to process the request within the normal time frame, they will contact you to give you a new expected completion date.

If money is owed to you as a result of the amendment, the ATO will pay you, including any interest. If you owe money, you will receive notice of an amended assessment with the amount due and due date. This may also include interest owed by you, which you can request be removed as you are the one who brought the error to the attention of the ATO.

If your Australian tax return had not yet been processed when the request for amendment was received, they will be processed jointly and you will only receive your notice of assessment, without a notice of amended assessment.

While it may seem easier to just ignore a found mistake, this could cause you problems with the ATO in the future. The process of asking for an amendment is fairly straightforward, with little chance of being penalised for your mistake. If you follow the correct procedure, you will be able to rest easy knowing that all of your tax affairs have been put in order.

DISCLAIMER: Many of the comments in this article are general in nature and anyone intending to apply the information to practical circumstances should seek professional advice to independently verify their interpretation and the information applicability to their own particular circumstances.

Finder survey: How do Australians pay their taxes?

Response75+ yrs65-74 yrs55-64 yrs45-54 yrs35-44 yrs25-34 yrs18-24 yrs
Bank transfer30.36%28.05%19.38%21.64%23.08%23.89%28.57%
Credit card21.43%15.85%9.38%14.04%17.58%14.44%7.69%
Debit card10.71%10.37%9.38%12.28%17.58%17.78%39.56%
Source: Finder survey by Pure Profile of 1004 Australians, December 2023

More guides on Finder

Ask a Question

You are about to post a question on

  • Do not enter personal information (eg. surname, phone number, bank details) as your question will be made public
  • is a financial comparison and information service, not a bank or product provider
  • We cannot provide you with personal advice or recommendations
  • Your answer might already be waiting – check previous questions below to see if yours has already been asked

Finder only provides general advice and factual information, so consider your own circumstances, or seek advice before you decide to act on our content. By submitting a question, you're accepting our 1. Terms Of Service and 6. Finder Group Privacy & Cookies Policy.

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

15 Responses

    Default Gravatar
    PeterSeptember 25, 2017

    Can you please tell me where I would find the “Claim type code letter” which I need for completing an amendment to my tax return?

    Default Gravatar
    AlexMarch 21, 2016

    Hi there,

    if I didn’t claim Medicare Levy Exemption part of tax whilst being on 457 working visa back to 2010-2011-2012-2013, can I do that now?

    Thank you!

      ShirleyMarch 21, 2016Finder

      Hi Alex,

      Thanks for your question.

      It’s recommended that you amend any of your tax returns if you think you’ve completed them incorrectly. Please get in touch with the ATO directly.

    Default Gravatar
    KeithMarch 10, 2016

    If I paid 97,000 in tax am I entitled to a refund

      ShirleyMarch 10, 2016Finder

      Hi Keith,

      Thanks for your question.

      Without knowing what your income is, I can’t answer this question. Please check the relevant marginal income tax rates that apply to you.

    Default Gravatar
    TanyaOctober 19, 2015

    Hi I put in a tax amendment for year 2013/2014 as I did not claim any deductions I faxed it to them and heard nothing after 50 days I then rang to be told it will be a further 20 days is there anything that I can do to make sure I get my rebate after the 20 days?

      ShirleyOctober 19, 2015Finder

      Hi Tanya,

      Thanks for your question.

      In this situation it’s best to contact the ATO for a confirmation that you’ll get your rebate after the 20 days.

      Sorry that we couldn’t be much of an assistance.


    Default Gravatar
    marianneSeptember 19, 2015

    Hi I’m in australia on a working holiday visa and was incorrectly informed by the ATO contact centre that I should put “not an australian resident for tax purposes” even though I worked in the same job and stayed in the same area.

    Therefore when doing my tax return with etax i received notice that i owed the ato money so rang them to try and sort it out and was advised that i need to send in an amendment form which i posted three weeks ago.

    Can it really take 50 business days as my visa is nearly up. Would it be worth contacting them to see if there’s a way to speed it up or do I just have to wait?

      ShirleySeptember 21, 2015Finder

      Hi Marianne,

      Thanks for your question and we’re sorry to hear about your situation.

      Unfortunately on the ATO website it states that it could take up to 8 weeks to amend your return. It may be worth contacting them and explaining the situation to see if the ATO can speed the process up.


Go to site