How to Get a Tax File Number (TFN) if You Are Under 18
A Step-by-Step Guide
Navigating Australia’s tax system for the first time can feel overwhelming, especially when you’re just starting your first job. One of the most important first steps for any young worker is getting a Tax File Number (TFN). This unique number is essential for managing your tax and superannuation, and this guide will walk you through exactly how to get one if you’re under 18.
What is a Tax File Number (TFN)?
A Tax File Number (TFN) is your personal reference number in the Australian tax and superannuation systems 1. You’ll need it for almost everything related to your finances, including starting a new job, lodging a tax return, applying for government benefits, opening a bank account, and managing your superannuation.
While it’s not compulsory to have a TFN, without one you’ll pay more tax than you need to and won’t be able to apply for government benefits or file your tax return online. Getting a TFN is free, and you can use it at any age.
Application Methods for Under-18s
For teenagers, the application method depends on your age and access to identity documents. Here are the main ways you can apply:
| Application Method | Age Requirement | Key Details |
| Online via myGovID | 15 years or older | The fastest method, but requires a Strong myGovID. |
| Australia Post | Any age | Complete a form online, then visit an Australia Post office. |
| Services Australia | Any age | Apply in person at a Centrelink service centre. |
| By Post | Any age | Mail a paper application form with certified documents. |
This guide will focus on the most common method for under-18s: applying through Australia Post.
Step-by-Step Guide: Applying for a TFN via Australia Post
This is the most straightforward method for most teenagers, as it doesn’t require a myGovID with a Strong identity strength. Here’s how it works.
Step 1: Complete the Online Application Form
First, you’ll need to fill out an online form on the Australian Taxation Office (ATO) website. You can access the form through the official ATO website, which will redirect you to an application portal managed by Australia Post.
1.Go to the ATO’s TFN application page and select the “Australian residents” option.
2.Follow the prompts to the Australia Post application portal.
3.You will land on a page that looks like this. Select “Start a new TFN application” and click “Continue.”
4.On the next page, you will be asked some eligibility questions. If you are applying for yourself, select “I am applying for my own TFN.” You will also need to enter your date of birth and agree to the terms and conditions.
Step 2: Print Your Application Summary
Once you have completed the online form, you will be provided with an application summary. You must print this summary, as it contains a unique application reference number that you will need for the next step.
Step 3: Visit a Participating Australia Post Office
Within 30 days of completing your online form, you need to visit a participating Australia Post office to complete your application. You will need to bring two things with you:
1.Your printed application summary
2.Your original proof of identity documents
Step 4: Provide Proof of Identity
This is the most important part of the process. You will need to provide original identity documents to prove who you are. The documents you need depend on your age 1.
For applicants aged 13 to 17:
You will need to provide one of the following combinations of documents:
- An Australian passport
- An Australian birth certificate and another document, such as a student ID card, a letter from your school, or a bank statement.
For applicants 12 years old or younger:
A parent or guardian must apply on your behalf and provide your birth certificate and their own identity documents.
Step 5: Sign and Lodge Your Application
At the Australia Post office, you will be asked to sign your application in front of a staff member. If you are between 13 and 15 years old, either you or your parent/guardian can sign. If you are 12 or under, your parent or guardian must sign for you.
Once you’ve signed and your identity documents have been verified, your application will be lodged. There is no fee for this service.
What Happens Next?
After you’ve lodged your application, the ATO will process it and mail your TFN to the postal address you provided. You should receive your TFN within 28 days 1. It’s important to be patient and not lodge another application during this time, as it can cause delays.
Once you receive your TFN, keep it in a safe place and don’t share it with anyone who doesn’t need it. You’re now ready to start your working life on the right foot!
Disclaimer: This article provides general information and does not constitute financial advice. Please consult with a professional for advice tailored to your specific circumstances. Information is current as of November 2025.