Sold in NZ, Taxed in the UK: What to Expect

Introduction

The absence of a comprehensive capital gains tax in New Zealand makes it an outlier compared to most OECD countries. So when Kiwis move overseas, facing a capital gains tax on their New Zealand assets can feel completely foreign, and it catches a lot of people out.

A few months after landing in London, a Kiwi couple I spoke with decided it was time to tidy up their finances back home. They’d settled into UK life, bought a car, and were finally ready to sell their old house in Tauranga. The property had more than doubled in value since they bought it, so they expected a tidy profit, until the UK Capital Gains Tax surprise arrived.

While New Zealand doesn’t have a general capital gains tax, the UK most certainly does. What they hadn’t realised was that once you become a UK tax resident, the British tax net catches not just your local earnings, but your worldwide income and gains, including the sale of your New Zealand home.

It’s a common scenario among Kiwis and Aussies who move to the UK and later sell property or shares back home. On the surface, it feels simple enough: you sell an asset in New Zealand, the money lands in your New Zealand bank account, and you assume it’s all dealt with under New Zealand rules. But the UK tax system has other ideas.

In today’s blog, we’ll break down how the New Zealand and UK tax systems interact when you sell a property or shares after moving abroad, what reliefs might help you, and how smart timing can make a world of difference.

NZ Rules in a Nutshell

I really want to cover how the UK tax bill for Kiwis living in the UK is impacted when selling their NZ-based assets, but before I do so, let’s take a quick look at how asset sales are taxed by the IRD in New Zealand.

New Zealand has no general capital gains tax, which often feels like a blessing when compared to the UK. However, that doesn’t mean gains are always tax-free. The IRD still taxes certain property sales and share transactions under specific rules, particularly when there’s an intention to make a profit or when the bright-line test applies.

The Bright-Line Test: Still in Play Even After You Leave

Since 1 July 2024, the bright-line period in New Zealand has been reduced back to two years. This means if you sell a residential property within two years of purchasing it, any gain is taxable as income in New Zealand.

The bright-line test applies even if you’ve moved abroad. If the property is in New Zealand and sold within that two-year window, Inland Revenue will treat the profit as New Zealand-sourced income, regardless of your residency status.

For example, if you bought an Auckland apartment in 2023 and sell it in 2025 for a $150,000 profit, that gain will likely be caught by the bright-line test and taxed at your marginal NZ income tax rate, which can be as high as 39 percent for top earners.

If you sell after the two-year period and the property wasn’t bought with an intention to resell at a profit, then generally no New Zealand tax will apply.

Any taxes paid in New Zealand can be used to offset any tax bill you might face in the UK.

When Your ‘Main Home’ Saves You from NZ Tax

New Zealand’s main home exclusion can protect you from bright-line tax, but it only applies if the property genuinely was your primary residence for most of the ownership period.

To qualify, you must have actually lived in more than half of the property’s area, and for more than half of the time you owned it. Simply calling it your main home or intending to live there won’t cut it. The IRD looks at where you genuinely lived, where your mail was sent, and where your personal belongings were kept.

The UK has similar rules, where CGT does not apply to the sale of your home.

Shares, Traders, and the No-CGT Myth

New Zealanders often take pride in the idea that there’s “no capital gains tax” on shares, but that’s only true for long-term investors. If you buy shares with the intention of selling them for profit, or if you trade frequently, the IRD may treat you as a share trader. In that case, your gains are taxed as ordinary income, at rates between 10.5 and 39 percent.

For most casual investors, though, gains from selling shares are not taxable. Dividends are taxed, but capital growth is not. Once you leave New Zealand and become non-resident, you’re no longer subject to the Foreign Investment Fund (FIF) regime either, so New Zealand generally stops taxing you on overseas investments from that point onward.

Non-Resident? Meet RLWT

If you’ve moved overseas and sell a New Zealand residential property within the bright-line period, you might find that your conveyancer withholds tax at settlement under the Residential Land Withholding Tax (RLWT) rules.

RLWT applies to “offshore persons” selling residential property that’s subject to bright-line. The withholding amount is usually the lower of 33 percent of the gain, 39 percent if you’re a high-rate taxpayer, or 10 percent of the gross sale price. The withheld amount is paid directly to the IRD to ensure the tax is collected before the funds leave the country.

In other words, even if you’re sitting in a café in London signing the sale documents, the IRD will still get its share first.

UK Rules That Catch People Out

The UK Taxes the World, Including Your NZ Gains

Once you become a UK tax resident, the UK tax system casts a much wider net than you might expect. The UK taxes worldwide income and capital gains for anyone who is tax resident there. That means if you sell a property or shares in New Zealand while living in the UK, HMRC wants to know about it, and may expect a share of the profit.

It doesn’t matter that the asset is located overseas or that the sale proceeds never make it into your UK bank account. The simple fact that you are UK resident for tax purposes is enough to trigger Capital Gains Tax (CGT) on the sale. This catches many expats off guard, especially those used to New Zealand’s lighter approach.

No Fresh Start: The UK Uses the Original Purchase Price

A common misconception is that when you move to the UK, your assets somehow get a “reset”, as though HMRC will only tax the gain that occurs from the date you arrived. Unfortunately, that’s not how it works.

When calculating CGT, the UK uses your original purchase price as the starting point, no matter when or where you bought the asset. So, if you bought a house in Wellington in 2005 and sell it in 2025 after moving to London, the UK will tax the entire gain from 2005 to 2025, not just the portion since you moved.

For Kiwis who’ve owned property or shares for many years, that can make for a surprisingly large taxable gain, even if New Zealand doesn’t tax it at all.

The 18% and 24% CGT Rates

For the 2024/25 tax year onward, the UK simplified its CGT rates. The old split rates (10%/20% for most assets and 18%/28% for residential property) have now been aligned. Individuals now pay 18 percent on gains that fall within the basic income tax band, and 24 percent on gains that fall into the higher-rate band.

This means that most Kiwis and Aussies working in the UK, who typically earn enough to reach the higher rate, will face 24 percent CGT on their property or share gains. You’ll also have access to a small annual allowance, but it’s not much help: as of 2025/26, the CGT exemption is just £3,000 per person, a steep drop from the £12,300 allowance available only a few years ago.

In short, the bulk of your capital gain will likely be taxable in the UK once you’re resident, regardless of whether it’s from a New Zealand house, share portfolio, or another overseas investment.

Main Home Relief: The UK’s 9-Month Rule

The UK’s equivalent of New Zealand’s main home exclusion is called Principal Private Residence Relief (PPR). It applies when the property you’re selling was once your main home.

If you lived in the property at any time during ownership, a portion of the gain is exempt from UK CGT. The exemption covers the years you lived there as your home, plus the final nine months of ownership, even if you’d already moved out by then.

For example, if you owned your New Zealand home for twenty years, lived in it for fifteen, and sold it five years after moving to the UK, around 15.75 years out of twenty would be exempt. Only the remaining period, roughly 4.25 years of the gain, would be taxable in the UK.

There is also some flexibility for temporary absences. You can usually still claim full PPR relief if you were away from the property for up to three years for any reason, provided you moved back in before eventually selling.

These reliefs can make a big difference for Kiwis who move to the UK, rent out their old home for a few years, and then sell. Selling within nine months of moving out can mean no UK tax at all, while waiting a few years can expose a sizeable part of the gain.

Real World Examples

To bring all of this to life, let’s look at how these rules actually play out for Kiwis who’ve moved to the UK and later sold property or investments back home. The numbers below are kept simple, but they highlight how easily a UK tax bill can sneak up on you.

Case Study 1: Selling Your Former NZ Home Five Years After Moving to the UK

Imagine a Kiwi who bought a house in Auckland in 2010 for NZD $500,000. They moved to the UK in 2019, rented the property out for a few years, and sold it in 2024 for NZD $1.2 million.

There’s no New Zealand tax to pay, since the sale happened well outside the two-year bright-line period.

But under UK rules, because they were UK tax resident at the time of sale, HMRC will want to tax the entire gain, converted into pounds at the relevant exchange rates.

If the gain converts to around £350,000, that’s potentially a £84,000 CGT bill at 24 percent, before any PPR relief.

If they’d lived in the house for nine years and rented it out for five, roughly nine-fourteenths of the gain (plus the final nine months) would be exempt under the UK’s PPR rules. The rest would be taxable.

Case Study 2: A Long-Held NZ Rental with No NZ Tax

Now lets look at a Kiwi living in London who owns a Wellington rental bought in 2008 for NZD $400,000, now worth NZD $900,000. The property has always been rented, so there’s no PPR relief in either country.

Since it’s well past New Zealand’s bright-line period, there’s no NZ tax at all. But because the owner is UK resident, HMRC taxes the gain from 2008 to the sale date.

Converted to pounds, say the total gain is £250,000. After the £3,000 CGT allowance, that’s a taxable gain of £247,000, producing a tax bill of about £59,000 at 24 percent.

It feels unfair, the UK taxing a property that’s never set foot on British soil, but that’s how the worldwide income rules work.

Case Study 3: Selling a Share Portfolio Built in New Zealand

Finally, take a Kiwi contractor who built an NZX share portfolio before moving to the UK. They invested NZD $100,000 over the years, and by 2025 it’s worth NZD $180,000. They decide to sell while living in London.

New Zealand won’t tax the sale unless they were a share trader, so the full gain looks tax-free back home. The UK, however, treats it as a £40,000 gain after conversion. With no foreign tax to offset, the contractor faces a UK CGT bill of about £9,000.

If they’d sold the shares before arriving in the UK, there would have been no UK tax at all, since they weren’t yet UK resident at the time of sale.

Avoiding Double Taxation

The NZ–UK Tax Treaty: Your Safety Net

The good news is that New Zealand and the UK have a double tax agreement (DTA) designed to stop the same income or gain from being taxed twice. In simple terms, it determines which country taxes first and allows the other to give credit for the tax already paid.

For capital gains, the DTA generally gives the country where the asset is located the first right to tax. So, if you sell a New Zealand property that falls inside the bright-line test, the tax is paid to Inland Revenue first. The UK then includes the gain in your worldwide income but offers a foreign tax credit for the NZ tax you’ve already paid.

How FIG Fits In

The FIG regime, introduced from April 2025, is the UK’s replacement for the old ‘non-dom’ system. If you’re within your first four years of UK tax residence and meet the conditions, you could elect into the Foreign Income and Gains (FIG) regime for a specific tax year. This election lets you ignore foreign income and gains altogether, which could help substantially lower your UK tax bill on a NZ asset sale.

However, this comes at a price: you lose your UK personal allowance and capital gains tax exemption for that year, and you can’t claim relief for any foreign losses.

For some people, this trade-off can make sense. If the gain on your New Zealand home or shares is large enough, and you qualify for FIG, it might be cheaper to claim FIG for that year, skip UK taxation entirely, and simply accept the loss of your allowances.

For others, especially those with ongoing UK income or smaller gains, the lost allowances can outweigh the FIG benefit. The key is to run the numbers before deciding. It’s an election you make year by year.

Timing and Planning Choices

The timing of your sale can make or break your overall tax outcome. If you’re still a New Zealand tax resident, any sale will be taxed solely under NZ rules. That means if your property sits outside the bright-line period, or qualifies as your main home, you could sell completely tax-free.

However, once you become UK tax resident, the UK taxes your worldwide gains. Selling after you move means the UK will tax the gain from the original purchase price, not from your date of arrival. So if you’re on the verge of relocating and plan to sell soon, it’s worth considering whether completing the sale before you trigger UK residency could save a large UK Capital Gains Tax bill.

Timing It Right to Keep Both Tax Offices Happy

The UK’s PPR relief gives you a 9-month grace period after moving out of your main home. If you sell within that period, the entire gain can often be sheltered from UK tax. Combine that with New Zealand’s main home exclusion, and it’s possible to pay no tax at all, in either country.

For example, a Kiwi couple who move to London in January and sell their former NZ home by September may find that both countries treat the sale as exempt. The key is making sure both the bright-line and PPR conditions are satisfied and that the sale falls within that overlapping relief window.

If you hold the property longer, the taxable portion grows month by month, as the UK begins taxing the part of the gain accrued after you stopped living there.

Avoid the UK’s ‘Temporary Non-Residence’ Trap

If you’ve already been UK-resident, then leave for a while, you’ll want to watch out for the temporary non-residence rule. This rule lets HMRC claw back tax on gains made while you were away, if you return to the UK within five full tax years.

In practice, if you move back to New Zealand, sell your UK or NZ assets while non-resident, and then return to the UK after just a couple of years, HMRC could still tax those gains on your return. To avoid this, you generally need to remain non-resident for at least five full tax years before coming back.

Note these rules only bite if you have been a UK tax resident for at least 4 of the last 7 years before leaving.

Don’t Forget the Exchange Rate Factor

Exchange rates can significantly shift your gain when converting from NZD to GBP. The UK calculates both the purchase and sale values in pounds, based on the exchange rates at those dates.

For example, if the NZ dollar strengthens against the pound between the time you bought and sold, your gain will look much larger in GBP, even if it’s the same in NZD terms. There’s no separate relief for currency movements, so this can amplify your UK tax bill unexpectedly.

Generally speaking, the New Zealand dollar is weaker now than it was 5, 10, or even 15 years ago. In fact a recent capital gains tax calculation that I did for a Kiwi showed that the shift in the FX rate worked hugely to their advantage to dramatically lower the UK capital gains tax bill.

Small Tweaks That Can Save You Thousands

1. Joint ownership: If you own the property with your spouse, both of you get the £3,000 CGT annual exemption, doubling your tax-free threshold to £6,000.
2. Offset losses: Capital losses on other investments can be used to reduce your taxable gain.
3. Track your timelines: Keep detailed notes on when you moved, when you stopped living in the property, and when the sale settled.
4. FIG regime option: If your gain is large and you qualify for the FIG rules, you could elect to ignore your foreign gains for that year and simply forgo your personal allowance. This can be a powerful tool if the UK CGT on your NZ sale would otherwise be substantial.

Timing, in this context, is everything. Whether you sell just before moving, just after arriving, or after you leave again, each scenario can lead to a completely different tax result. A little planning and record-keeping can turn what might have been a hefty tax bill into a much more manageable outcome.

Summary

Selling New Zealand property or shares after moving to the UK can turn into a tax nightmare if you don’t plan ahead. New Zealand’s rules are relatively straightforward, no general capital gains tax, just the bright-line test and some clear exceptions for your main home, but once you’re UK tax resident, HMRC wants to hear about every gain, wherever in the world it happens.

The key points to remember are simple:

1. The bright-line test still applies even after you’ve moved overseas, and Residential Land Withholding Tax may be deducted automatically if you’re non-resident.
2. The UK taxes worldwide gains, using your original NZ purchase price as the cost basis. There’s no reset when you arrive.
3. CGT rates of 18% or 24% now apply across both property and shares, with a small £3,000 annual exemption.
4. PPR relief can protect the part of your gain related to your main home, including the final nine months after you move out.
5. The FIG regime can be used strategically if you qualify, particularly when you’ve sold a property with a big gain. It can save you from UK tax on that sale, though you’ll lose your personal allowance and capital gains allowance for the year.
6. Timing is everything. Selling before becoming UK resident, or within nine months of leaving your home, can make a huge difference. The same goes for staying out of the UK long enough to avoid the temporary non-residence rules.
7. And finally, keep your paperwork. Purchase contracts, improvement costs, RLWT certificates, exchange rate records, and proof of tax paid, all of it helps protect you when reporting and claiming credits.

At No Worries Accounting, we help New Zealanders and Australians in the UK make sense of the cross-border tax maze. Whether you’re selling property, cashing in shares, or planning your move back home, we can help you map out the best timing and structure for your situation.