What is an IRD number?
An Business IRD number is a unique tax identification number issued by Inland Revenue (IR) — New Zealand’s tax authority. It is 8 or 9 digits long and is used to track all your tax obligations including income tax, GST, and student loan repayments. Every person who earns income, studies, or runs a business in New Zealand must have one. Without an IRD number, your employer is legally required to deduct tax at the highest “no-declaration” rate of 45 cents in the dollar.
Your IRD number stays with you for life — you do not need a new one if you change jobs, move cities, or start a business. A sole trader uses their personal IRD number for their business.
Student IRD number vs business IRD number
Student / personal IRD number
Used by individuals, employees, students, and sole traders. One number covers all your personal tax including part-time work and student loans.
Business IRD number
Required for registered companies (Ltd), partnerships, trusts, and incorporated societies. Separate from the owner’s personal IRD number.
Who needs an IRD number?
Documents required
How to get a student / personal IRD number — step by step
Check your eligibility
You must have a NZ address and a valid identity document (passport, NZ birth certificate, or NZ driver licence) before applying.
Apply online via myIR
Visit ird.govt.nz and go to “Get an IRD number.” You can apply online if you have a NZ passport or NZ driver licence. Overseas passports require the paper form (IR742).
Online applicants verify instantly using RealMe or their document details. If applying by paper, certified copies of identity documents must be included with form IR742.
Enter your details
Provide your full legal name, date of birth, NZ address, email, and tax residency status. Students should also indicate if they have a student loan to link it correctly.
Submit and wait
Online applications are usually processed within 8–10 working days. Paper applications take up to 15 working days. Your IRD number is sent by post to your NZ address — it cannot be emailed.
Give your IRD number to your employer
Once received, give your IRD number to your employer or StudyLink. Also complete a tax code declaration form (IR330) so the correct tax rate is applied to your income.
International students: Apply for your IRD number as soon as you arrive in NZ — do not wait until you find a job. You need a NZ address first. If you start work without one, your employer must tax you at 45%.
How to get a business IRD number — step by step
Register your company first
Before applying for a business IRD number, register your company on the NZ Companies Office website (companiesoffice.govt.nz). This gives you a Companies Register number you will need in the IRD application.
Have your personal IRD number ready
As a director or owner, you must already have your own personal IRD number before your company can get one. If you don’t have one yet, complete step 1–6 above first.
Download form IR596
Go to ird.govt.nz and search for “IR596” — this is the IRD number application form for non-individual entities including companies, partnerships, and trusts.
Fill in company details
Complete the form with your company name, Companies Register number, registered address, nature of business activity, financial year end (most businesses use 31 March), and director details.
Submit the form
Post the completed IR596 form to Inland Revenue, PO Box 39050, Wellington Mail Centre, Lower Hutt 5045. There is no online submission option for company IRD numbers — it must be posted.
Receive your business IRD number
Processing takes 8–10 working days. Your business IRD number is mailed to the registered company address. Use it immediately to register for GST (if turnover exceeds $60,000/year) and set up myIR online.
Sole trader tip: If you are a sole trader (not a registered company), you do NOT need a separate business IRD number. Use your personal IRD number for all business income and expenses.
