I’M A NZ TAX RESIDENT WITH OVERSEAS INVESTMENT PROPERTY. DO I HAVE TO PAY NRWT? OR AIL?

NZ tax resident overseas rental property NRWT. Was that what you were looking for? Well, you’ve come to the right page. If you are wondering “I’m a NZ tax resident with overseas investment property. Do I have to pay NRWT? Or AIL?” we can help. Before we get into the recent changes (2026) to this matter, here is a high-level overview:

30-Second Summary

• If you’re a NZ tax resident with an overseas rental property and an overseas mortgage, you may need to deduct Non-Resident Withholding Tax (NRWT) from the interest you pay.
• The alternative is registering as an Approved Issuer and paying the Approved Issuer Levy (AIL) instead, allowing interest to be paid at a 0% NRWT rate.
• That overseas mortgage is also a financial arrangement under IRD’s FA rules — which can require you to spread income/expenses over the loan’s term and account for foreign currency movements, separate from the NRWT/AIL question.
• Whether you have to spread income or can simply account on a cash basis depends on whether you qualify as a “cash basis person” — and IRD updated this threshold for the 2025–26 income year onward.
• A base price adjustment (BPA) is required when the arrangement ends (e.g. loan repaid, property sold) regardless of which basis you use.

The Basic Question: NRWT or AIL?

The best starting point is IRD’s own flow-chart:

Basically, if you have overseas investment property and a mortgage with an overseas bank, you might have to pay NRWT.

What Is NRWT?

NRWT is Non-Resident Withholding Tax. If you’re paying interest, dividends, or royalties to people (or banks — e.g. a mortgage with an overseas bank) who aren’t New Zealand tax residents, you generally need to deduct NRWT from those payments. There are exceptions — see IRD’s NRWT guidance for detail.

What Is AIL, and How Is It an Alternative?

The other option is paying AIL (Approved Issuer Levy). If you pay interest to a non-associated, non-resident lender and want to pay it at a zero rate of NRWT, you have to apply to Inland Revenue to become an approved issuer. Instead of deducting NRWT, approved issuers pay a levy on the securities they register with Inland Revenue. More detail is available directly from IRD.

Don’t Stop at NRWT/AIL — Your Mortgage Is Also a Financial Arrangement

Here’s the part that’s easy to miss: an overseas mortgage on a rental property isn’t just an NRWT/AIL question. It’s also a financial arrangement for the purposes of IRD’s Financial Arrangements Rules (FA rules) — IRD specifically lists “a loan to buy a rental property” as an example.

The FA rules exist to make sure income and expenditure from arrangements like loans and foreign currency accounts are recognised in the right tax year, and — critically for overseas property owners — they disregard the usual capital/revenue distinction and can require you to account for foreign currency gains and losses, not just interest.

In practice, this means two separate questions apply to your overseas mortgage:

1. NRWT or AIL — how the interest you pay to your overseas lender is taxed at source.
2. The FA rules — how you recognise interest expense and foreign exchange movements on that loan in your own NZ tax return over time.

Are You a “Cash Basis Person”?

This is where the FA rules bite hardest for property investors: if you’re not a “cash basis person,” you may need to use a formal spreading method to recognise income and expenditure over the term of the loan, rather than simply on a cash-received/cash-paid basis.

IRD updated the cash basis person thresholds, effective from the 2025–26 income year onward. You’re a cash basis person if you meet either of these tests:

• Your income and expenditure from all financial arrangements, calculated on an accrual basis, is under $200,000; or
• Your total financial assets and liabilities (added together, ignoring plus/minus signs) are less than $2 million.

That second point catches people out: if you have $1.5 million in financial assets and $600,000 in financial arrangement debts, your total is $2.1 million — over the threshold — even though your net position looks modest. “Total” means adding the absolute values together, not netting them off.

If you qualify as a cash basis person, you can generally return interest and other income as you actually receive or pay it, converted to NZD at the time — much simpler than formal spreading. You’ll still need to complete a base price adjustment when the arrangement ends.

What Happens When the Arrangement Ends: The Base Price Adjustment

Whether or not you’re a cash basis person, when the financial arrangement ends — the loan is repaid, refinanced in a way that ends the arrangement, or the property is sold — you must perform a base price adjustment (BPA). This is a wash-up calculation taking into account everything paid and received over the life of the arrangement. If the result is positive, it’s taxable income; if negative, whether it’s deductible depends on the normal rules.

This is exactly where currency movements can create a surprise: a large swing in exchange rates (or even a smaller swing on a large loan balance) can turn what felt like a straightforward mortgage repayment into an unexpected tax bill — or, sometimes, a deduction.

Key Takeaways

• Two separate regimes apply to an overseas mortgage on rental property: NRWT/AIL governs the tax on interest you pay to your overseas lender; the FA rules govern how you recognise that loan’s income and expenses in your own return.
• AIL can reduce your NRWT rate to zero, but only if you’ve registered as an approved issuer before relying on it.
• Whether you’re a “cash basis person” changed for 2025–26 onward — check both the $200,000 accrual income/expenditure test and the $2 million total financial assets and liabilities test; you only need to meet one.
• A base price adjustment is required when the arrangement ends, regardless of your cash basis status — and foreign currency movements can generate real, sometimes unexpected, taxable income (or losses).
• This area is genuinely complex — IRD says so themselves. Get advice before assuming cash accounting is available to you, or before an overseas loan is refinanced or repaid.

Still Not Sure Where You Stand?

Overseas property, foreign currency loans, and the FA rules interact in ways that are easy to get wrong and expensive to get wrong retroactively — particularly around the base price adjustment. If you’re not sure whether you’re a cash basis person, whether AIL is worth registering for, or what your exposure looks like at repayment or sale, get in touch with us. We work with property investors on exactly this kind of cross-border tax position. (And if you need help with NZ investment property, we can assist with that too)