Does this apply to my own home?

No, these rules apply to residential rental properties only. Interest on your owner-occupied home loan is not deductible — that has not changed.

When does the full deductibility start?

From 1 April 2025, you can claim 100% of your mortgage interest on residential rental properties. For the 2024/25 tax year (which straddles this date), you will need to apportion based on when the interest was incurred.

Can I claim back interest I could not deduct in previous years?

Generally, no. Interest that was denied under the old rules cannot be claimed retrospectively. However, consult with your accountant about your specific circumstances and any transitional rules that may apply.

What is the difference between interest deductibility and ring-fencing?

Interest deductibility determines whether you can claim interest as an expense. Ring-fencing determines what you can offset losses against. You now get full interest deductibility, but any resulting rental loss can still only be offset against rental income (not wages or other income).

Does it matter when I bought my property?

Not anymore. From 1 April 2025, all residential rental properties qualify for full interest deductions regardless of purchase date. The old distinctions based on whether you bought before or after 27 March 2021 no longer apply.

Interest Deductibility Rules for NZ Landlords

After years of restricted interest deductibility under the previous government's policy, the rules have been fully reversed. From 1 April 2025, property investors can once again claim their full mortgage interest as a tax-deductible expense — a significant boost for landlords across New Zealand.

What Changed?

The interest limitation rules were introduced in 2021 by the previous Labour government with the aim of reducing property speculation. These rules progressively restricted the ability of residential landlords to deduct mortgage interest from their rental income.

Under the old rules, properties purchased after 27 March 2021 could not deduct any interest, while older properties faced a phase-out schedule. New builds had a special exemption allowing full deductions.

All of that is now history. The coalition government repealed the interest limitation rules, and from 1 April 2025, the playing field is level again.

The New Rules (From 1 April 2025)

What You Can Claim:

100% of mortgage interest on residential rental properties is now deductible
Applies to all properties regardless of purchase date
No distinction between new builds and existing properties
No phase-out or percentage limitations

This represents a return to the pre-2021 position where landlords could fully deduct their financing costs against rental income.

What This Means for Your Cash Flow

The restoration of full interest deductibility can significantly improve the after-tax position of rental properties. Let us look at an example:

Example: Impact of Restored Deductibility

Mortgage: $600,000 at 6.5% interest
Annual interest: $39,000
Tax bracket: 33%
Tax benefit from deduction: $12,870 per year
Monthly improvement: Over $1,000 better cash flow position

For investors who purchased after March 2021 and had no deductibility at all, this is a substantial improvement. Properties that were cash flow negative may now be neutral or positive.

Ring-Fencing Rules Still Apply

While interest deductibility has been restored, it is important to remember that the rental loss ring-fencing rules remain in place. These are separate rules that still apply.

Ring-Fencing: What It Means

If your rental property makes a loss (including after interest deductions), you cannot offset that loss against your salary, wages, or other income. The loss is "ring-fenced" and can only be carried forward to offset against future rental profits.

This means the old strategy of deliberately running rental losses to reduce your overall tax bill is no longer effective. However, the losses are not lost — they accumulate and reduce your tax when your properties do become profitable.

What About Properties Purchased During the Restriction Period?

If you purchased a property between 2021 and 2025 when the interest limitation rules were in effect, you may have accumulated losses that you could not previously claim. Under the new rules:

From 1 April 2025 onwards, you can claim full interest deductions on current interest payments
Interest that was previously denied is generally not able to be claimed retrospectively
Consult with your accountant about your specific situation and any transitional provisions

Record Keeping Requirements

Even with simplified rules, good record keeping remains essential. You should track:

Interest paid on each loan used for rental property
How loans are allocated if they are cross-secured across properties
Any ring-fenced losses carried forward from previous years
Other deductible expenses for each property

Good records support accurate tax returns and protect you if IRD queries your deductions.

Interaction with the Bright-Line Test

If you sell a property and the bright-line test applies, interest deductions (along with other costs) can be claimed against the taxable gain. With full deductibility now restored, this interaction is simpler than during the restriction period, but professional advice is still recommended when selling.

The Bottom Line

The repeal of interest limitation rules is welcome news for property investors. Full interest deductibility from 1 April 2025 restores a key tax benefit and improves the economics of residential rental investment.

However, remember that ring-fencing rules still apply, and tax rules can always change with future governments. Work with a qualified accountant to ensure you are claiming the right deductions and structuring your portfolio effectively.

Interest Deductibility Rules for NZ Landlords

Disclaimer:

🎉 Major Update: Full Interest Deductibility Restored

Key Takeaways