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What is a tax file number?

Find out why you need a TFN, where to find it and how to keep your TFN and personal details safe.

Last updated 18 June 2024

We also have an Easy Read version of this – What is a tax file number?

About your TFN

A tax file number (TFN) is your personal reference number in the tax and superannuation systems.

It is free to apply for a TFN.

Your TFN is:

  • a unique number (usually 9 digits)
  • an important part of your identity
  • yours for life – you keep your TFN even if you change jobs or name, move interstate or go overseas.

Where to find your TFN

If you already have a TFN, you can find it:

  • in the ATO app or your ATO online account if you have a myGov account linked to the ATO
  • on your income tax notice of assessment
  • on some of the letters we send you
  • on a payment summary or income statement from your employer
  • on your superannuation account statement.

If you use a registered tax agent, you can also ask them for your TFN.

Contact us as soon as possible if you think your TFN is lost, stolen or being misused.

If you don't already have a TFN

You can apply for a TFN at any age. However, if you apply online using myGovID, you must be 15 years old or older and have a passport.

Not having a TFN

You don’t have to have a TFN, but without one, your employer or financial institution must withhold more tax from payments they make to you. Without a TFN, you:

  • can't apply for government benefits or allowances, such as JobSeeker
  • can't lodge your tax return online
  • can't apply for an Australian business number (ABN).

When you will get your TFN

You generally receive your TFN within 28 days after we receive your completed application and required identity documents. We will send your TFN to the postal address you put on your application or your myGov inbox, depending on how you apply.

For Australian citizens (15 years old or older) with an Australian passport, our beta application process may mean you receive your TFN much sooner.

If you haven't received your TFN after 28 days, contact us.

Keep your TFN and personal details safe

Make sure you protect your identity by keeping all your personal details secure, including your TFN.

Someone only needs basic details, such as your name, date of birth, address, myGov details or TFN, to commit identity fraud or scams.

Only disclose your TFN to people and organisations that require it for legitimate reasons, such as:

  • us – the Australian Taxation Office (ATO) – when discussing your tax records
  • your employer when you start work
  • your bank or financial institution
  • other government agencies to claim benefits
  • your superannuation fund
  • your university.