Tax on Investments and Savings in New Zealand

In New Zealand, tax on savings mostly arrives through the back door. Nobody asks you to calculate it, and in most cases nobody sends you a bill. The provider withholds it before your money reaches you, so the cost of an investment is easy to underestimate until you compare the headline return with what actually turns up in the account.

The awkward part is that the amount withheld is not set by how much you earn in any general sense. It is set by the wrapper your money sits in — a bank account, a managed fund, a share portfolio, or a KiwiSaver scheme. Change the wrapper, and the rate changes with it, even when the underlying investment is identical.

How We Researched This Guide

The rates and rules here come from Inland Revenue's own published material rather than a secondary summary of it — the prescribed investor rate page, its pages on multi-rate portfolio investment entities, and its guidance on PIE income for New Zealand residents.

Two things are worth flagging before the detail. First, you can’t quietly opt out of withholding — the payer must apply a rate, and if you have given none, it applies a default on your behalf. Second, the rate attached to an account matches your income through a set of thresholds, and that is where most of the surprises sit.

The Quick Summary (60-Second Version)

If you only read one part of this page, read this bit.

  • New Zealand investment tax is usually withheld by the provider before the return reaches you.
  • Bank interest is taxed through resident withholding tax, at a rate that depends on your circumstances and whether you have made a rate election.
  • Managed funds are multi-rate PIEs, taxed at your prescribed investor rate of 10.5%, 17.5% or 28%.
  • Dividends sit outside the PIE system, and you must include a dividend from a listed PIE in your income tax return.
  • KiwiSaver is also a multi-rate PIE, so the fund’s return is taxed at your PIR.
  • If you never supply a rate to a PIE, the default of 28% is applied to the investment return.

The Tax That Leaves Before You Do

Withholding works on the same principle as PAYE on a wage. The payer calculates the tax and sends it on, so the individual never handles the money. A bank deducts resident withholding tax from your interest and credits you the balance. A managed fund applies your prescribed investor rate to the income the fund earns on your behalf.

The consequence is that the tax becomes invisible. No invoice, no payment date that lands in your inbox, and nothing that changes what you file. Most people first notice the rate they have been on when they sit down to compare funds, or when an accountant asks them for it.

A second consequence matters more. Because the rate is attached to the account rather than the person, an account opened years ago can still run on the rate you qualified for back then.

Four Wrappers and How Each One Is Taxed

New Zealand does not treat every investment the same way. Money typically sits in one of four places, and each has its own tax collection mechanism.

Money held in a bank account

Interest from a bank account or a term deposit is subject to resident withholding tax. The applicable rates are 10.5%, 17.5%, 30%, 33%, 39% and 45%, depending on your circumstances and whether you have made a rate election. A 0% rate applies where the recipient has RWT-exempt status.

An election brings the withholding close to your actual marginal rate. Where the rate applied is too high, you are lending Inland Revenue money until the year is squared up. Where it is too low, the shortfall can come back as a bill.

Money in a managed fund

A managed fund is generally a multi-rate portfolio investment entity. Tax is charged at your prescribed investor rate, which for New Zealand tax residents is one of 10.5%, 17.5% or 28%, and multi-rate PIE income is capped at 28%. Resident withholding tax is not paid on multi-rate PIE income — the PIR takes its place.

You must give the fund your IRD number, and for a new investment you have six weeks to do so before the account is closed. If you don't give the fund a PIR, the default rate of 28% applies.

Shares held directly

Listed shares sit outside the PIE system. Dividends are taxed under the dividend rules, with imputation credits and withholding operating at the company and shareholder level. If you receive a dividend from a listed PIE rather than a multi-rate PIE, that dividend must be included in your income tax return and resident withholding tax rules apply to it.

Overseas shares introduce a further layer of complexity through the foreign investment fund rules, which are covered in a separate guide on this site.

KiwiSaver

KiwiSaver is a multi-rate PIE, so the investment return inside the fund is taxed at your PIR in exactly the way a managed fund is. What makes KiwiSaver unusual is that it is taxed at both ends — the employer's contribution is taxed on the way in, and the return the fund earns is taxed as it goes.

One comfort specific to KiwiSaver is that its PIE income does not affect Working for Families or student loan entitlements, which is not true of every multi-rate PIE.

Where the money sits How tax is collected What sets the rate
Bank account or term deposit Withheld as resident withholding tax RWT rate of 10.5%, 17.5%, 30%, 33%, 39% or 45%; 0% if RWT-exempt
Multi-rate PIE fund Charged on the fund's income Your PIR — 10.5%, 17.5% or 28%
Listed shares Dividend rules, imputation and withholding Your marginal position
KiwiSaver PIR on the return, ESCT on the employer contribution Your PIR, plus the ESCT band
Dividend from a listed PIE Included in your income tax return Resident withholding tax rules

The table is the argument in miniature. Every row is a return on money you have set aside, yet the mechanism — and therefore the amount — changes at each line.

Four terracotta pots in a row on a bench, each holding a different plant

Why the Wrapper, Not the Return, Sets the Rate

Each wrapper has its own rules for determining how much income exists in the first place, which is why the rates differ. A multi-rate PIE works out the fund's assessable income, allocates it across investors in proportion to their share, then applies each investor's PIR. A bank does something far simpler — it applies a withholding rate to the interest it pays you.

This is why two people with identical portfolios can pay different amounts. The wrapper sets the mechanism, and your PIR or RWT election sets the number. A cap also sits on the PIE side: multi-rate PIE income cannot be taxed above 28%, no matter how high the investor's other income climbs.

The Default Rate Is Not a Neutral Fallback

It is tempting to treat the default as fair — something the system applies when you have not made a choice. It is not neutral. When you don’t supply a PIR, the system applies 28% to the investment return, and 28% is the highest of the three rates available to most individual investors.

Where your correct rate is 10.5% or 17.5%, the default overtaxes you through the year. You can often correct the position in myIR or with an IR215 form, but that is an extra step, and most people only take it once they notice the gap.

There is a second trap. If you are eligible, you can choose only 10.5% or 17.5%, and an incorrect PIR can mean you pay more tax at the end of the year.

Questions You Might Have

Which rate actually applies to me?

The prescribed investor rates for New Zealand tax residents are 10.5%, 17.5% and 28%, and the rate depends on your income in either of the two income years before the tax year in question. You cannot choose a PIR of 0%, except in a narrow case for individuals with a four-year temporary tax exemption who invest in a zero-rate PIE.

Do I have to tell my fund when my income changes?

Yes — the obligation sits with you, not the fund. The rate turns on your income in the two income years before the relevant tax year, so a change in earnings can move you between bands without the fund having any way to notice.

Does PIE income count towards Working for Families or a student loan?

PIE income from a retirement savings scheme such as KiwiSaver does not affect Working for Families or student loans. Other multi-rate PIE income does count, and you can adjust it in myIR or on an IR215 form.

What about a dividend from a listed fund rather than a managed fund?

A dividend from a listed PIE is not treated as multi-rate PIE income. You must include it in your income tax return, and resident withholding tax rules apply instead.

Is the amount withheld the final answer?

Usually, but not always. Withholding approximates your liability. If you supplied the wrong PIR, or gave none where an election was available, the year-end position can differ from what was deducted.

What Matters Most

Tax on an investment is decided before you ever see the return, and the deciding factor is the wrapper rather than the amount. Bank interest is taxed at resident withholding tax, managed funds and KiwiSaver are taxed at your prescribed investor rate, and directly held shares are taxed under the dividend rules.

The two things genuinely worth checking are the rate attached to each account and whether that rate still reflects your income. Both are quietly wrong more often than people expect, and neither one announces itself. Fixing an out-of-date PIR is a two-minute job that pays you back every year afterwards.

Every rate and threshold in this guide is taken from Inland Revenue's published guidance. Where a figure could not be confirmed against that source, it does not appear here.