With the advancement in technology, the ATO can audit much deeper and broader than in previous years. If your tax return is not correct, they can easily identify errors and start an investigation. Therefore, if you think you can get away with the addition of a few additional deductions, you should think twice.

When do you need to correct a tax return?

You may need to correct a tax return if you have:

  • made an error when answering a query
  • forgotten to add some capital gain or income
  • forgotten to claim a deduction
  • had something change after filing a tax return, such as
    • getting a revised payment summary
    • your employer updating or finalising your income statement
    • repaying an income amount you were overpaid.

The ATO doesn’t charge a fee if you request an amendment and you are not required to send in another tax return unless the ATO asks you to. Make sure to keep a copy of your request for your records if you are submitting a letter. If you use ATO’s online services, you can access your details at any time.

How to request an amendment to your tax return after making a mistake?

Check the following option to lodge an amendment to your tax return:

  • Online through ATO online

You can lodge an amendment to your income tax return by using ATO’s online services. This process may take 20 days to process. Irrespective of how you lodged your original income tax return, you can submit an amendment to your assessment online. You need a myGov account to access ATO’s online services.

  • Paper amendment form

If you can’t submit your amendment application through the online method, you can send the form to the ATO to request for amendment of the tax return of individuals. This process may take 50 business days to process the application.

  • Through a registered tax agent

You can seek help from a tax return accountant to complete the amendment to your income tax return on your behalf. Your tax agent can complete and lodge the tax return amendment electronically for you using the Practitioner Lodgment Service (PLS). Even if the original tax return was not made through PLS, an amendment to a tax return can be made through the PLS. The tax agent can alternatively send the form to the ATO, lodgment for amendment of a tax return by tax professionals. It may take 50 business days to process the application.

  • By sending a letter

If you don’t amend your tax return online or using the form, you can send a letter to the ATO. It may take up to 50 days to process the request. Your letter must include the required information, including copies of documents that support your request and the following information:

  • your tax file number (TFN)
  • your full name
  • your postal address
  • a daytime phone number (if convenient) or mobile number
  • your details of bank account (in case there is a refund amount)
  • the year mentioned on the tax return you want to amend – for example, 2023
  • the item number your change relates to and the description
  • the amount of income or deductions you’re adding or subtracting and the accurate sum of the amount (if relevant)
  • the amount of tax offsets you’re adding or subtracting and the accurate sum of the amount (if relevant)
  • the reason for the change or description of how you made the mistake
  • your signature along with the dated declaration.

You or your representative must send this by attaching all documents to the ATO. There is a different time limit for lodging an amendment, such as:

  • for individuals and sole traders, 2 years
  • for small and medium businesses, 2 years
  • 4 years for other taxpayers.


The blog shares information on lodging amendments to tax returns if you have made a mistake and apart from this, time limit for submitting amendments to your tax return. For help regarding amendments to your income tax return, you can contact Reliable Melbourne Accountants.