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Lost Tax File Number – Is it serious?

Written by Bryn Robinson \u2022 Bookkeeping Manager
Published on 27 Sep 2016

When you first receive your TFN, you are told how important it is to keep it secure and private.

Despite this, a lot of people don’t realise how serious the repercussions can be for failing to protect their TFN from landing in the wrong hands. You will have the same tax file number even if you change your name, jobs, move interstate or go overseas. You can’t even start a business without having a tax file number. It’s a crucial part of your identity as an Australian Citizen. It’s your personal reference number in the tax and super systems.

Poor or negligent security of your TFN could result in misuse of your personal details, and even identity theft.


Who can I trust with my tax file number?

Access to your tax file number should only be limited to the following people and organisations:

  • The Tax Office;
  • Other Australian Government agencies;
  • Employers;
  • Superannuation Funds;
  • Higher education providers;
  • Registered tax agents, solicitors and accountants; and
  • Banks and other financial institutions.

If a request is made for your tax file number by a representative not listed above, you should NOT provide your tax file number.


What should I do if I’ve lost my tax file number?

If you have forgotten or lost your TFN, you should:

  • Look for a notice or letter from the Tax Office;
  • Log on to your myGov account; or
  • Ask your tax agent.

You can also call 13 28 61 to find out your tax file number. The number is available to call 8.00am and 8.00pm Monday to Friday.


I suspect my tax file number may have been stolen or access without my permission!

If you feel that your TFN may have been stolen or accessed by an unauthorised third party, you should contact the Tax Office immediately on 1800 467 033. They can apply security measures that allows them to monitor unusual activity concerning your TFN

Poor or negligent security of your TFN could result in misuse of your personal details, and even identity theft.


My TFN is stolen! What do I do?

If you suspect misuse your tax file number may be stolen. The best thing to do is to phone the ATO’s Client Identity Support Centre on 1800 467 033. The number is available between 8.00am and 6.00pm, Monday to Friday.

The Client Identity Support Centre provides a support service for taxpayers who have had their identities stolen or misused. Information, advice, and assistance will be provided to enable you to re-establish your identity.

If you need help finding your TFN, contact us.

Check out another recent blog in this category.

Bryn has spent nearly 20 years with Fitzpatrick Group Building Better Businesses. Now a Director and also General Manager, Bryn assists our business clients in the areas Accounting, Taxation, and Business Growth.
Authour \u2022 Bryn Robinson

Bookkeeping Manager, Fitzpatrick Group

Post Categories: Tax Essentials

Lost your TFN?


  1. Chandrakanta chalise

    I have lost my tfn
    I had applied through online
    I had screenshot the refrence number but the photo was deleted unknownly.
    I hadn’t received it in my postal address also.
    What to do now?
    Help me out.

    • Shaun Da Silva

      Hi Chandrakanta, I’ve forwarded your email address to our team. One of our professionals will be in touch with you shortly.

  2. Amanda

    I’ve lost my tax file number, I’ve been out of the country for 4 years and I’m planning to go back to Australia this year. However, I can’t seem to find my TFN and I don’t remember the email, user or password created to access myGov. I need help please.

    • Shaun Da Silva

      Hi Amanda, we’ve contacted you directly via email to help you resolve this issue.

  3. Ahsan

    My TFN has been stolen by a Third party. What should I do?

    • Shaun Da Silva

      Hi Ashan, if you think or suspect that your TFN has been stolen you should immediately contact the ATO’s Client Identity Support Centre on 1800 467 033. They will be able to assist you between 8.00am and 6.00pm, Monday to Friday.