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How self-assessment affects you

Last updated 3 March 2016

Self-assessment means the Tax Office uses the information you give on your tax return to work out your refund or tax debt. You are required by law to make sure you have shown all your assessable income and claimed only the deductions and tax offsets to which you are entitled. The Tax Office does not take any responsibility for checking the accuracy of the details you provide in your tax return. However, at a later date the Tax Office may examine the details contained in your tax return more thoroughly by reviewing specific parts, or by conducting an audit on your tax affairs.

What are your responsibilities?

It is your responsibility to lodge a tax return that is signed, complete and correct. Even if someone else – including a tax agent – helps you to prepare your tax return, you are still legally responsible for the accuracy of your information.

What if you lodge an incorrect tax return?

Our audit programs are designed to continually check for missing, inaccurate or incomplete information. If you become aware that your tax return is incorrect, you must contact us straight away.

Initiatives to complement self-assessment

There are a number of initiatives administered by the Tax Office which complement self-assessment. Examples include:

  • if you take reasonable care with your tax affairs, you will not receive a penalty for honest mistakes – but please note that a general interest charge on omitted income or over-claimed deductions and tax offsets could still be payable
  • the process for applying for private rulings
  • your entitlement to interest on early payment or over-payment of a tax debt, or the process for applying for an amendment if you find you have left something out of your tax return.

Do you need to ask for a private ruling?

If you have a concern about the way a tax law applies to your personal tax affairs, you may want to ask for a private ruling.

A private ruling will relate just to your situation. Write to the Tax Office describing your situation in detail and ask for advice. To do this, complete an Application for a private ruling for individuals. You should lodge your tax return by the due date, even if you are waiting for the reply to your private ruling. You may need to request an amendment to your tax return once you have received the private ruling.

The Tax Office publishes on its website all private rulings issued. What we publish will not contain anything which could identify you.

You can ask for a review of a private ruling decision if you disagree with it, even if you have not received your assessment. Details of the review procedures are sent to you when the private ruling decision is made. For more information on private rulings, visit the Tax Office website at