Getting a tax number is dull, and it's also the single piece of paperwork that decides how much of your first pay cheque you actually keep. Australia calls it a Tax File Number, or TFN. New Zealand calls it an IRD number. Both are free. Both take a bit of admin to sort. And both countries default to the exact same number if you skip this step: 45%. Here's how to apply for each, what order to do it in, and the mistakes that cost people real money in their first few weeks.
Why you can't just skip this
It isn't paperwork for its own sake. Both tax offices assume the worst about you until you tell them otherwise.
Every payslip you get in Australia or New Zealand is taxed according to the number you give your employer, or the number you don't. Skip it, and both countries reach for the same fallback: the top rate, on everything, from your very first shift. It isn't a fine and it isn't lost for good. Once you're sorted, the excess comes back to you. But it's real money sitting somewhere else for weeks while you wait, and it costs nothing to avoid by applying in your first few days.
Australia: getting your Tax File Number Australia
You can only apply once you've actually landed, so there's no getting ahead of this one.
What you'll need
A passport, an email address and an Australian mobile number. You'll also need a postal address in Australia, which is the trickiest part if you land straight into a hostel: your TFN arrives as a letter, and hostels don't always hold mail for guests who've moved on. A friend's address, your Airbnb host's, a PO box or Australia Post's free Post Restante counter service all work if you don't have anywhere more permanent yet.
How to apply
Working holidaymakers on a 417 or 462 visa use the ATO's online application for foreign passport holders, not the form built for Australian residents. It's free, takes about 20 minutes, and you don't post or upload any documents: the ATO checks your identity against your visa instead. You do need to already be in Australia to use it.
New Zealand: getting your IRD number New Zealand
You don't need a bank account first, whatever you might have heard.
What you'll need
Your passport details and your Immigration New Zealand application number, plus one more piece of ID to confirm who you are: your most recent overseas tax number if you have one, a New Zealand bank account number in your name, or completed customer due diligence with a bank. Only one of those three is required, so a bank account genuinely isn't compulsory before you start.
How and when to apply
This is the "new arrival" process, and it lets Inland Revenue confirm your identity straight from Immigration New Zealand's own records rather than asking you to post anything in. You need to apply through it by the date your visa says you must arrive by. Miss that date, and you're routed into the slower process for people already living in New Zealand instead. Applying online usually gets your number back within about 2 working days, by text or email. Going in person to an NZ Post store or an AA Driver Licensing Agent works too, though it usually takes closer to 10 working days by post.
What order to actually do this in
Australia and New Zealand don't quite work the same way, so don't copy one country's order onto the other.
Australia
Sort a local SIM early if you can: the TFN application itself asks for an Australian mobile number, on top of the local number your bank will want for verification codes. Apply for your TFN as soon as you land, since it can only be lodged once you're actually in the country. Open your bank account in parallel rather than waiting on your TFN: most banks let you start before it arrives, and you just add it once you have it. The moment your TFN letter turns up, hand it to your employer with a Tax File Number declaration so the 45% withholding stops.
New Zealand
New Zealand's own order still holds: IRD number, then bank account, then SIM. The IRD application doesn't need a bank account first and usually comes back within a couple of days online, so there's no reason to wait on it before sorting your bank account and SIM card.
Common mistakes
The ones that cost people real money, or a genuinely annoying phone call to fix.
Working your first shifts without applying at all. The 45% (or no-notification) rate applies from your very first pay, not after some grace period. Apply in your first few days, even before your first shift.
Giving your employer the number without the declaration form. A TFN or IRD number on its own isn't enough. Your employer also needs a completed Tax File Number declaration in Australia, or a tax code declaration (the IR330) in New Zealand, before they can apply the right rate.
Writing down the wrong number, or a friend's by mistake. Both numbers are personal and both stay with you for life. Double-check what you hand over: a transposed digit means your pay gets taxed under someone else's details, which is genuinely painful to unpick later.
Losing the letter and assuming you need a whole new number. You don't. It's the same number for as long as you're alive, in both countries. In Australia, it sits in your myGov account once you link the ATO to it. In New Zealand, logging into myIR shows you yours again.
Missing New Zealand's "arrive by" deadline for the fast process. Apply after the date your visa says you must arrive by, and you're bumped into the slower process for people already living in the country instead of the streamlined new-arrival one.
FAQs
Quick answers to the questions we get asked most about TFNs and IRD numbers.
Do I need a TFN or IRD number before I start working?
Not strictly before your first shift, but apply within your first few days regardless. Every day you delay is a day taxed at the top rate: 45% in Australia without a TFN, and the equivalent no-notification rate in New Zealand without an IRD number and a completed tax code declaration.
What happens if I work before I have one?
Your employer has to withhold tax at the top rate on everything you earn, 45% in both countries, until you hand over the number and the matching declaration form. You don't lose that money permanently. It comes back once you're sorted, and in Australia, once you lodge your tax return.
Do I need a New Zealand bank account before I can apply for an IRD number?
No. A bank account is only one of three ways to prove your identity for the new-arrival application, alongside an overseas tax number or completed customer due diligence. Plenty of people get their IRD number before they've opened an account at all.
Can I apply for my Australian TFN before I land?
No. The online application for foreign passport holders requires you to already be in Australia, since it checks your identity against your visa. Get your passport, an Australian mobile number and a postal address sorted, then apply as soon as you've landed.
What if I lose my TFN or IRD number letter?
You don't need a new one. Both numbers are yours for life. In Australia, your myGov account shows it once it's linked to the ATO. In New Zealand, logging into myIR does the same.