Applying for a Tax File Number in Australia is free, and most residents can finish the online form in about ten minutes and then verify their identity at a participating Australia Post outlet within 30 days.1Australian Taxation Office. Australian Residents – TFN Application A TFN is a unique nine-digit number that stays with you for life across the tax and superannuation systems, even if you change jobs, names, or move overseas. You aren’t legally required to have one, but without it your employer or bank must withhold tax from your payments at the top rate.2Australian Taxation Office. What is a Tax File Number?
Who Can Apply
Australian residents can apply regardless of age or employment status. A child can get one from birth if needed, and retirees who’ve never had one can still apply. Foreign passport holders who are permanent migrants, or temporary visitors on a visa that allows work in Australia, can also apply. People living overseas who earn Australian-sourced income use a separate pathway, covered further down.
One boundary to note: if you’re managing a deceased person’s estate that earns income after the date of death, that estate needs its own trust TFN rather than the individual application described here.3Australian Business Register. Deceased Estate
Documents to Gather Before You Start
The ATO sorts acceptable identity documents into two tiers. Primary documents carry the most weight: an Australian passport, a full birth certificate (not an extract), or a citizenship certificate. Secondary documents provide supporting proof and include a driver’s licence, a current tertiary or secondary student ID card with your photo, or a marriage certificate.4Australian Taxation Office. TFN Application or Enquiry for Individuals – Instructions
If you’re applying by post, send certified copies, not originals. Never mail your original documents to the ATO, as they may not be returned. The people who can certify copies as true and correct include:5Australian Taxation Office. Copies of Identity Documents for Applicants in Australia
- Justice of the Peace
- Solicitor or barrister
- Judge
- Police officer
- Medical practitioner registered with the Medical Board of Australia
- Bank, building society, or credit union officer with at least five years of service
- Minister of religion authorised to celebrate marriage
- Sheriff’s officer
- Commissioner of Declarations (Queensland only)
The ATO does not accept certified copies of digital identity documents, so work from physical originals.
The Three Ways Residents Can Apply
Online, Then Verify at Australia Post
This is the most common route. Complete the online application on the ATO website, then take your application summary and your original identity documents to a participating Australia Post outlet within 30 days. You’ll sign the application there to finalise it.1Australian Taxation Office. Australian Residents – TFN Application Miss the 30 days and you’ll have to start a new online application.
In Person Through Services Australia
Centrelink customers can apply at a Services Australia service centre. If you’ve authorised Centrelink to receive your TFN from the ATO, choose “To give to Centrelink” as your reason for needing one; the ATO will then send the number to both you and Centrelink once it’s processed.1Australian Taxation Office. Australian Residents – TFN Application
Paper Application by Post
If you can’t apply online or visit an office in person, order the paper form (NAT 1432) through the ATO’s Publications Ordering Service, then mail it with certified copies of your identity documents to the address printed on the form. Aboriginal and Torres Strait Islander applicants can use an alternative form (NAT 1589), which requires a referee to complete a proof of identity reference.1Australian Taxation Office. Australian Residents – TFN Application
Applying from Outside Australia
If you’re a foreign resident for tax purposes living outside Australia and you earn Australian-sourced income, download and complete a different paper form (NAT 2628) from the ATO website.6Australian Taxation Office. Tax File Number – Application or Enquiry for Individuals Living Outside Australia Permanent migrants and temporary visitors who are already in Australia use the standard resident process above.
The reason to bother: without a TFN, tax is withheld at the highest rate from every payment. For context, the foreign resident tax rates for 2025–26 start at 30 cents per dollar on income up to $135,000 and rise to 45 cents per dollar above $190,000.7Australian Taxation Office. Tax Rates – Foreign Resident With no TFN on file, you’re taxed at the top rate regardless of what you actually earn.
Applying for a Child
Children can get a TFN at any age. Whoever signs the form depends on the child’s age:4Australian Taxation Office. TFN Application or Enquiry for Individuals – Instructions
- 12 or under: a parent or guardian must sign on the child’s behalf.
- 13 to 15: either the child or a parent or guardian can sign.
- 16 or older: the applicant signs their own application.
Children may need a TFN earlier than parents expect. A savings account that earns interest, income from a family trust, or part-time work all trigger top-rate withholding if there’s no TFN on file.
What Happens After You Apply
The ATO usually processes applications within 28 days of receiving a completed form and verifying your identity. Your TFN is posted to the residential address you gave on the application.1Australian Taxation Office. Australian Residents – TFN Application If you haven’t heard anything by then, contact the ATO. Keep the notification letter somewhere secure at home rather than in your wallet.
Why the Wait Is Worth It
Once you have the number, share it with a short list of parties: your employer, your bank or other financial institution, your superannuation fund, and your registered tax agent. Only give it to an employer after you’ve actually started work, not during the interview.
If you don’t provide a TFN to a new employer and haven’t claimed an exemption or told them you’ve applied for one, they must withhold at the top tax rate plus Medicare from every payment. If you’ve told them you’ve applied but haven’t handed over the number within 28 days, top-rate withholding starts from that point.8Australian Taxation Office. Tax File Number and Withholding Declarations Banks apply the same principle to interest-bearing accounts, withholding 47% of any interest earned (45% tax plus 2% Medicare levy) when there’s no TFN on the account. You can claim overpaid tax back when you lodge your return, but the money is tied up until then.
When you start a job, your employer will ask you to complete a TFN declaration, either their electronic version or the paper form NAT 3092. You fill in your TFN, personal details, whether you’re claiming the tax-free threshold from this employer, and whether you have a HELP, VET Student Loan, or similar debt.9Australian Taxation Office. How to Complete the Paper TFN Declaration Form – Payee That declaration is what tells payroll to withhold at the correct rate rather than the default top one.