NZ Rentals, UK Taxes: Landlord's Guide

Introduction

I speak with numerous UK-based Kiwis every month who have a rental property back in New Zealand, and the conversation often starts with either (a) “I pay tax in New Zealand on my rental, so I’m sorted,” or (b) “My rental does not make a profit, so there is nothing to declare.” If you are living and working in the UK and you have a rental back home, you have two tax authorities to keep happy. New Zealand taxes the rent because the property is there. The UK taxes it because you are here. The double tax agreement ensures you do not pay twice on the same income, but it only works if you report correctly in both countries and claim the relief in the right place.

Where most people come unstuck is not the theory; it is the practical detail. Many are simply not aware of how the rules work and just want to make sure they are compliant. The UK requires you to put the New Zealand figures on a Self Assessment return, in GBP, for a tax year that does not exactly match New Zealand’s dates. The UK also treats some costs differently. From April 2025, New Zealand allows full mortgage interest deductibility again, but the UK does not allow a deduction and instead gives a basic rate credit for finance costs. New Zealand lets you depreciate chattels in a rental. The UK does not; it gives relief only when you replace domestic items.

In this blog I will explain what to file, where to claim foreign tax credit relief, and why your UK bill can be higher than you expect even when you have already paid tax in New Zealand. If you get the basics right, you will file twice but pay only what is properly due.

Just Quickly: Tax residency and who taxes what

If you are UK tax resident, HMRC taxes your worldwide income. That includes rent from a New Zealand property, even if every dollar stays in New Zealand. You report it on your UK Self Assessment.

New Zealand taxes New Zealand-sourced rental income whether or not you are New Zealand resident. Most UK-based Kiwis will be non-resident for New Zealand tax on everything else, but the rental stays taxable in New Zealand because the property is there.

The UK–New Zealand double tax agreement prevents the same income being taxed twice. In practice you file in both countries, pay the New Zealand tax first, then claim Foreign Tax Credit relief on your UK return for the New Zealand tax paid. The result is that you pay the higher of the two countries overall, not both in full. The relief only works if you actually report the income in both places and keep evidence of the New Zealand tax.

The New Zealand side (and what changes the UK picture)

If you are non-resident for New Zealand tax you still file in New Zealand each year for this income, typically on an IR3NR return, and you pay New Zealand income tax on the net rental profit. Each joint owner files for their own share.

New Zealand’s list of allowable deductions is broad and fairly similar to the UK, but two items significantly impact your UK position:

1. Mortgage interest. From 1 April 2025 New Zealand again allows a full deduction for interest on residential rental mortgages. The UK does not allow a deduction for individual landlords. Instead, you record the interest separately and receive a basic rate credit equal to 20 per cent of the finance costs. The result is that your UK taxable profit can be higher than the New Zealand figure even when the cash position feels the same.
2. Depreciation on chattels. In New Zealand you can depreciate chattels in the rental such as appliances, carpet and furniture. The UK does not give depreciation on residential lets. Instead, you may claim Replacement Domestic Items Relief when you replace a like-for-like item that is provided for tenants’ use. The initial purchase is not deductible in the UK calculation.

Side note on GST registration in NZ. If you offer short-stay accommodation, for example Airbnb or similar, watch the New Zealand GST position. Long-term residential letting is exempt, but short-stay is a taxable activity once your gross turnover exceeds NZD 60,000 in any 12-month period. If you cross that threshold you need to register and account for GST in New Zealand. Note that GST registration does not impact the UK tax calculation – you just need to ensure the figures you report exclude any GST (which you would also do on your NZ tax return).

The UK return: what you actually report

If you’re UK tax resident and earn rent from a New Zealand property, you’ll need to file a Self Assessment tax return and include the Foreign pages (SA106).

Here’s what to include:

Currency Conversion: All figures must be converted from NZD to GBP. HMRC publishes both monthly and annual average exchange rates. Choose one method and stick with it consistently year after year.

Income: Report the total rent you received for the year. HMRC accepts NZ rental accounts drawn up to 31 March, as this is close enough to the UK year end (5 April). No need to adjust for those extra few days.

Expenses: You can deduct everyday running costs such as:

1. Property management and letting agent fees
2. Accountancy fees
3. Insurance and council rates
4. Safety checks and routine repairs

Capital improvements (like adding an extension or upgrading a kitchen) are not deductible. The UK also doesn’t allow depreciation of the property or contents. Instead, you can claim Replacement Domestic Items Relief when you replace things like furniture, appliances, carpets or curtains on a like-for-like basis. The initial cost of furnishing the property is not deductible.

Travel Costs: You can only claim travel that is “wholly and exclusively” for the rental business. HMRC will challenge mixed-purpose trips to New Zealand (e.g. holiday plus property inspection) unless you can show clear, separate evidence of the business element.

Finance Costs (Mortgage Interest): Unlike in New Zealand, mortgage interest is not deducted to arrive at rental profit in the UK. Instead:

1. Work out your rental profit before finance costs.
2. Report your mortgage interest separately.
3. Claim a tax credit equal to 20% of those costs.

For higher-rate (40%) or additional-rate (45%) taxpayers, this means you don’t get full relief at your marginal rate. The effect is that a property breaking even in New Zealand can still show a taxable profit in the UK.

Practical Reporting Tip

HMRC accepts New Zealand rental accounts to 31 March as close enough to the UK tax year end of 5 April. You can use your 31 March figures on your UK Self Assessment without carving out 1–5 April, provided you apply this approach consistently each year.

Lets See a Worked Example

OK, with the theory behind us, let’s look at how this works in practice. Terry bought a house in Christchurch for NZ$780,000, with a NZ$550,000 mortgage at 4.75% interest (around NZ$26,125 a year). The property rents for NZ$600 per week (about NZ$31,200 annually), with a property manager charging 10% of the rent (NZ$3,120 per year). On top of that, there are running costs such as insurance, council rates, and minor repairs of around NZ$2,000 a year, plus NZ$2,000 of chattel depreciation under NZ rules. For simplicity, we’ll use an exchange rate of NZ$2 = £1. Terry is UK tax resident and already a higher-rate taxpayer (40%) through his UK salary.

Step 1: New Zealand tax calculation (year to 31 March 2026)

1. Gross rent: NZ$31,200
2. Less property management fees: (3,120)
3. Less other expenses: (2,000)
4. Less mortgage interest (100% deductible from April 2025): (26,125)
5. Less depreciation on chattels: (2,000)

NZ taxable loss = NZ$2,045

No tax is payable in New Zealand because the property shows a loss.

Step 2: UK tax calculation (to 5 April 2026, using NZ accounts to 31 March)

1. Gross rent: £15,600
2. Less management fees: (1,560)
3. Less other expenses: (1,000)
4. Depreciation ignored (not allowed in UK)
5. Mortgage interest not deducted in profit calculation

UK taxable rental profit before finance costs = £13,040

Mortgage interest (reported separately) = £13,063

Step 3: UK tax liability

1. Tax on £13,040 profit at 40% = £5,216
2. Finance cost credit: 20% × £13,063 = £2,613

UK tax due (before NZ credit) = £2,603 (~NZ$5,206)

Step 4: Apply foreign tax credit

1. NZ tax already paid: £0 (loss-making under NZ tax rules)

Final UK liability = £2,603 (~NZ$5,206)

The end result? Terry’s Christchurch rental makes a cash loss once the mortgage is paid, owes no tax in New Zealand, but still triggers over NZ$5,000 of tax in the UK. And remember, this example assumes an interest-only mortgage. If capital repayments were included, the cashflow would be even worse.

Foreign Tax Credit Relief – how you avoid paying twice

When you declare your New Zealand rental income on your UK return, you can claim Foreign Tax Credit Relief for the NZ income tax you have already paid on the same profit.

The credit is limited to the amount of UK tax due on that income. In practice, this means you usually end up paying whichever country’s tax bill is higher overall.

A Quick Note on Stamp Duty Land Tax (SDLT)

If you buy a UK home while you still own your New Zealand property, the UK will usually treat your purchase as an “additional” property. That triggers the higher Stamp Duty Land Tax (SDLT) rates – an extra 3% surcharge on top of the normal residential bands. You also lose first-time buyer relief once you already own a dwelling anywhere in the world.

Two More Points to Watch

1. Replacement of main residence rule
2. You can avoid or reclaim the 3% surcharge only if your UK purchase is a direct replacement of your previous main home. That old home must have been owned by you (or your spouse/civil partner), actually lived in as your main residence, and then sold or otherwise disposed of. If you sell it within three years after buying the new UK place, you can apply to HMRC for a refund. A New Zealand rental you never lived in will not qualify.
3. Non-resident buyer surcharge.
4. If you haven’t been in the UK for at least 183 days in the 12 months before completion, the extra 2% non-resident surcharge applies on top of everything else. The good news is that if you later meet the 183-day test in the 12 months after completion, you can usually claim a repayment from HMRC.

What This Can Look Like in Practice

Say you buy for £500,000 while you still own your NZ rental. You’ll pay the normal SDLT bands plus the 3% additional property surcharge. If you’re also classed as non-resident for SDLT purposes at completion, add another 2% across the price. That combined uplift can easily push the bill from £15,000 to around £40,000 – a material cost for expats buying before selling their old home.

Practical Tips

1. Replacing your former home? If your NZ property was genuinely your main residence and you plan to sell it, aim to sell within three years of the UK purchase and then claim the 3% refund. Keep clear evidence it was your home (e.g. bills, correspondence, tax records).
2. Close to the 183-day rule? If you’re near the threshold, consider timing completion so you meet it and avoid the 2% surcharge. Otherwise, be ready to claim a repayment once you’ve built up the days after completion.
3. Budget early. Both surcharges apply to the full purchase price and must be paid within 14 days of completion, so cash flow planning really matters.

Summary

At the end of the day, the golden rule is simple: file twice, pay once, if you get the credits right. You’ll always need to lodge in both countries: New Zealand, because the property is there, and the UK, because you live there. The double tax agreement is what stops you from paying the same tax bill twice, but it only works if you’ve reported the income properly in both places and claimed the relief in the right way. If you cut corners, miss a detail, or assume “no profit means no return,” that’s when problems start.

The issues we see when chatting with kiwis are:

1. UK’s restriction on mortgage interest (only a 20% credit, not a deduction).
2. Depreciation differences (NZ allows it on chattels, the UK doesn’t).
3. SDLT surcharges if you buy in the UK while still holding property back home.

These rules catch plenty of smart Kiwis out, not because they’re careless, but because the cross-border detail is fiddly and easy to mis-step.

We deal with this every day for expats just like you. Message us, and we’ll map out your exact filing steps, keep both taxmen happy, and help you avoid nasty surprises.