What is a tax file number declaration form and how do you fill it in?

Why does the Tax File Number Declaration form matter?

Without this form on file, your employer cannot apply the correct tax rate:

• Default withholding without the form: 45% (the top rate)
• Correct withholding for working holiday makers: 15%
• The difference is $320 per week on $1,000 of earnings
• The excess is reclaimed only at tax time, months later

Submitting the form promptly when you start work is one of the most important things you can do to ensure your pay is correct from day one.

How should working holiday makers fill in the form?

The critical sections for working holiday makers:

• Full name, date of birth, address: personal details (use your Australian address)
• TFN: enter your 9-digit Tax File Number
• Residency: select Working Holiday Maker (not Australian Resident, not Foreign Resident)
• Tax-free threshold: select No (the threshold is for residents, not working holiday makers)
• HELP/VSL debt: usually No for working holiday makers (unless you have an Australian study loan)
• Other questions: complete honestly based on your circumstances

The Working Holiday Maker selection is what triggers the 15% rate. Selecting "Foreign Resident" by mistake causes 30% to be applied. Selecting "Australian Resident" and "Yes" to tax-free threshold causes the wrong rate plus a future tax debt.

Where do you get the form?

The form is provided by your employer:

• Your employer should give you a copy when you start work
• Some employers provide it digitally through their onboarding system
• Some use a printed paper version

Once you complete it, you hand it back to your employer (not to the ATO). They keep it on file and use it to set up your payroll.

What if you do not have your TFN yet?

You can still start work without your TFN, but the temporary setup needs adjusting:

1. Apply for your TFN immediately if you have not done so
2. Show your employer the TFN application reference number
3. Complete the Tax File Number Declaration form with the reference number
4. Update the form with your actual TFN once it arrives (within 28 days)

Until your TFN is on file, the 45% rate may apply. See our article on TFN reference numbers for what to do in the interim.

What about a new job?

Every new employer needs their own Tax File Number Declaration form:

• Your TFN does not transfer between employers automatically
• A previous employer holding your form does not cover the new one
• Complete a new form for every job, including casual roles

If you have already started a new job and the form was filled in incorrectly, submit a corrected form to your employer. They update payroll going forward, and any excess tax is recovered through your tax return.

What if you suspect your form was filled in wrong?

If your payslip shows withholding at 45%, 30%, or any rate other than 15%, the form may have been completed incorrectly:

1. Check your copy of the form against the correct answers above
2. Submit a corrected form to your employer
3. Get in touch with our team to check your withholding and recover any overpaid amounts through your tax return