Interest-only mortgages tend to get a bad rap, and not without reason. Used recklessly, they can lead to financial stress and ballooning debt. But in the right circumstances, with the right strategy, they can be a very smart move-especially for investors or those managing short-term cashflow pressures.
Why Banks Are Cautious About Interest-Only Mortgages
Banks in New Zealand are required to lend responsibly, and that means encouraging borrowers to actually reduce their debt-not just service the interest. The Reserve Bank takes a dim view of long-term interest-only lending, especially for owner-occupiers nearing retirement. As a result, most banks will only allow interest-only terms for a limited time: typically two years for owner-occupied homes and up to five years for investment properties.
Are Interest-Only Mortgages Still Available?
Yes-but approval depends on your circumstances. Banks assess interest-only applications carefully, particularly for owner-occupiers. For investors, interest-only remains a common strategy now that full interest deductibility has been restored from April 2025.
When Interest-Only Makes Financial Sense
1. Paying off higher-interest debt
If your mortgage is 7% but your credit card is 20%, it's clear where your money should go. Going interest-only frees up cash to knock back expensive short-term debt.
2. Repaying a family loan
Many first home buyers get help from parents, often with the understanding that repayment comes first. Switching to interest-only can be a temporary solution.
3. Managing cashflow during major life events
Starting a business, having children, or taking parental leave can all create short-term income drops.
The Investment Strategy Angle
Property investors typically structure their lending so that personal home loans are paid down first, while investment loans remain interest-only (because the interest is tax-deductible). From April 2025, full interest deductibility has been restored for all residential investment properties, making interest-only strategies attractive again for investors.
Restrictions and Reversions: What to Expect
Once your interest-only term expires, the bank will usually automatically switch the loan to principal and interest. If you want to extend your interest-only term, you'll need to apply again. Be prepared for more scrutiny if you're over 50.
High LVR? You'll Struggle to Get Approved
If your loan-to-value ratio ([LVR)](/blog/what-does-lvr-mean) is over 80% and you're applying for an interest-only loan on your owner-occupied home, most banks will say no.
Who Should Consider Interest-Only Mortgages?
Interest-only loans aren't for everyone. But they can be useful if:
- •You have a mixed portfolio and want to keep the investment debt high (for tax reasons)
- •You need to prioritise other debts in the short term
- •You're being forced to switch back to principal and interest, but you'd be better off staying interest-only for now
Make a Plan Before the Clock Runs Out
Interest-only loans should always be a tool, not a lifestyle. When used right, they can help you unlock capital, invest elsewhere, or smooth out your finances. But without a clear plan to eventually reduce your debt, they can just delay the inevitable.
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