NZ TaxContractorsWithholding Tax28 March 2026 · 7 min read

IR330C vs IR330: understanding contractor tax forms in NZ

What the IR330C and IR330 forms are, who needs which one, how schedular payment rates work, and what happens if you get it wrong.

If you're a contractor in New Zealand, you've probably been asked to fill out an IR330C or IR330 — and wondered which one you need, what the rates mean, and what happens to the tax that gets deducted.

Here's a plain-English explanation of both forms.

The fundamental difference

IR330 is the standard Tax Code Declaration form used by employees. Your employer uses it to determine which tax code to apply to your PAYE — M, ME, SB, S, SH, ST, or SL. If you're starting a new job, your employer gives you an IR330.

IR330C is the Tax Rate Notification for Contractors. It's used when a business engages you as a contractor (not an employee) and is required to withhold schedular payments (withholding tax) from what they pay you.

The key distinction: if you're an employee, you get an IR330. If you're an independent contractor receiving schedular payments, you get an IR330C.

Tip: Not sure if you're an employee or contractor? IRD has a detailed test. The short version: contractors control how they do their work, use their own tools, and can work for multiple clients. Employees are directed by their employer. The label in your contract doesn't determine your status — the nature of the work does.

What are schedular payments?

Schedular payments are payments made to contractors for specific types of work listed in Schedule 4 of the Income Tax Act 2007. If your work is on that list, the person paying you is legally required to deduct withholding tax and pay it to IRD on your behalf.

Types of work that attract schedular payments include: - Labour-only building work - Agricultural, horticultural, and related services - Road transport - Entertainment work (film, TV, music, events) - Professional services (accounting, IT, consulting, engineering, legal, medical) - Security services - Cleaning services

Note: most contractors providing professional services are covered. If you're a freelance developer, consultant, designer, or similar, you're almost certainly in scope.

IR330C: what rates do you select?

The IR330C asks you to select a withholding tax rate. Your options are:

Standard rate (20%) — the default if you haven't applied for a special rate. IRD withholds 20% of your gross contract payment.

Reduced rate (e.g. 10%, 15%) — you can apply to IRD for a lower rate if the standard 20% will create an overpayment based on your expected annual income. Apply using myIR before the contract starts.

Zero rate (0%) — available only if you're a non-resident contractor or meet specific exemption criteria.

No withholding tax — if you hold a valid certificate of exemption from IRD (requires an application and IRD approval).

Tip: If your income from the contract will put you in a lower tax bracket, apply for a reduced rate before the contract starts. The application takes a few days through myIR. You'll get a letter confirming your rate to give to the payer.

How the withholding tax flows

Here's what happens when withholding tax is deducted:

1. You complete the IR330C and give it to the business engaging you 2. They pay you, withholding the rate you specified 3. They pay the withheld amount directly to IRD on your behalf 4. At the end of the tax year, you file your IR3 (individual return). The withheld amounts are credited against your total tax liability 5. If more was withheld than you owe, you get a refund. If less was withheld, you pay the shortfall

The withholding tax isn't your final tax — it's a pre-payment toward your annual liability.

What goes on your invoice

When you're subject to schedular payments, your invoice should show:

- Your gross fee (the full amount for the work) - The withholding tax deducted (as a negative line, e.g. WT 20% — −$200.00) - The net amount payable by the client

Example:

Consulting services — $1,000.00 Withholding Tax 20% — −$200.00 Net payable — $800.00

The client pays you $800 and pays $200 to IRD separately.

PayWren supports this: set the withholding tax rate on the client record and invoices automatically show the gross, WT deduction, and net payable.

Tip: Always show the full gross amount on your invoice even though you only receive the net. Your income for tax purposes is the gross — the WT deduction is just a prepayment mechanism.

What if no IR330C is provided?

If you start work without providing an IR330C, the payer must withhold tax at the no-notification rate of 45% — the highest possible rate. This is IRD's penalty for non-compliance and is deliberately punitive.

Always provide your IR330C before invoicing. If you've already invoiced without one, provide it immediately and ask the payer to apply the correct rate going forward.

Important: Some businesses try to avoid the withholding tax obligation by treating workers as contractors when they're really employees. If you're misclassified, IRD can assess PAYE, KiwiSaver, and ACC levies going back years — for both you and the business. Get advice if you're uncertain.

IR330C checklist

Before starting any contract engagement:

  • Confirm your work falls under Schedule 4 (professional services almost always do)
  • Determine the right withholding tax rate — apply for a reduced rate if needed
  • Complete and sign the IR330C
  • Provide it to the payer before your first invoice
  • Show WT separately on your invoices (gross, deduction, net)
  • At year end, file your IR3 and claim credit for withheld amounts

Invoicing sorted in minutes.

PayWren is built for NZ freelancers — GST-compliant invoices, expense tracking, and IRD-ready reports. Free to start.

Get started free →