What is a tax file number (TFN)?


A tax file number, also known as a TFN, a unique number given to every taxpayer by the ATO to help the government keep track of your tax return and other services. You will only get one TFN over the course of your entire lifetime, even if your name or residency status changes. Your TFN is a very important piece of confidential information and as such, you should make sure to keep it secure.

Do I need a TFN?

It is not legally required that you obtain a TFN. However, you will need one in order to

  • Lodge a tax return
  • Apply for income assistance or support payments, such as pensions or benefits from Centrelink or the Department of Veterans’ Affairs
  • Claim the Family Tax Benefit (FTB)
  • Make or receive payments under PAYG withholding
  • Start work or change jobs, etc.

Naturally, this means that almost everyone needs a Tax File Number. The few exceptions to this rule include those who are Australian nonresidents for tax purposes who only receive interest from an Australian bank account, dividends from Australian shares, or royalty payments.

How do I find my TFN?

Before you apply for a TFN, check to make sure you don’t have one already. If you do have a TFN, you can find it from

  • Your income tax notice of assessment
  • Correspondence from the ATO
  • A payment summary from your employer
  • Your superannuation member statement
  • Your registered tax agent

Read our blog about finding your TFN. If you still can’t find your TFN, you can phone the ATO at 13 28 61.