Mortgage Payoff vs Investing: The Pre-Retirement Debt Decision

You've worked hard for decades, building equity in your home while contributing to KiwiSaver. Now, as retirement edges closer, you're facing a decision that feels more emotional than mathematical: direct every spare dollar toward killing that mortgage, or keep investing for growth?

Your neighbour swears by one approach. Your financial-savvy colleague insists on the other. And the financial websites? They all seem to give different answers depending on which assumptions they're using.

Here's what makes this decision so personal: it's not just about the numbers. It's about interest rates versus investment returns, tax treatment, and something harder to quantify but equally important - the psychological freedom of owning your home outright as you enter retirement.

Let's start with the spreadsheet version of this decision, because the numbers do matter, even if they don't tell the complete story.

When you pay off your mortgage early, you're effectively earning a return equal to your mortgage interest rate. If you're paying 6.5% on your home loan, every extra dollar you pay down saves you 6.5% in interest you won't have to pay. That's a guaranteed, risk-free return.

Compare that to investing. According to FMA guidance on investment returns, historically diversified portfolios have returned various rates depending on asset allocation and time horizon, but future returns are never guaranteed. Growth-oriented investments have historically provided higher long-term returns than conservative options, but with significantly more volatility.

The traditional financial planning math says: if you can reliably earn more after tax from investing than your mortgage interest rate, invest. If your guaranteed savings from paying down the mortgage exceeds likely investment returns, pay the mortgage.

But here's where it gets complicated in the New Zealand context.

Unlike rental property investors who can claim mortgage interest as a deduction (with current phase-out rules from IRD), your home mortgage interest isn't tax-deductible. You're paying that 6.5% with after-tax dollars.

On the investment side, the tax picture varies dramatically:

• KiwiSaver funds are taxed as Portfolio Investment Entities (PIEs), with tax rates between 10.5% and 28% depending on your income. Many New Zealanders pay 17.5% or 28% PIR rates on their KiwiSaver returns.
• Direct shares outside KiwiSaver face different rules. NZ shares generate dividends (often with imputation credits) and capital gains (generally not taxed unless you're trading). Australian and international shares may fall under the Foreign Investment Fund (FIF) rules, which can create tax on unrealized gains.
• Term deposits and savings are taxed at your marginal rate, which could be 30%, 33%, or 39% depending on your income.

This means the after-tax return on investments can be significantly lower than the headline rate, narrowing the gap between investing and mortgage payoff.

The mortgage-versus-investing debate looked very different in 2021 when you could lock in a mortgage at 2.5%. With rates that low, the mathematical case for investing was much stronger, even accounting for taxes and risk.

In 2024-2025, with mortgage rates in the 6-7% range, the equation has shifted. The Reserve Bank tracks current mortgage rates, and while they've come down from their 2023 peaks, they're still substantially higher than the ultra-low period.

A 6.5% guaranteed return from paying down your mortgage is actually quite attractive when you compare it to:

• Conservative KiwiSaver funds returning 3-4% before tax
• Balanced funds targeting 5-6% over the long term (with significant volatility)
• Term deposits offering 5-6% (fully taxable at your marginal rate)

The higher your mortgage rate, the more compelling the case for paying it down becomes, especially as you get within 5-10 years of retirement when you have less time to ride out investment volatility.

Here's what the calculators can't capture: how will you feel entering retirement with a mortgage payment hanging over your head?

For many New Zealanders, the emotional and psychological benefit of owning their home outright is substantial. It's not irrational to value this, even if it costs you some theoretical investment returns. Consider:

• Reduced fixed expenses: Entering retirement without a mortgage payment means you need less income to cover your basics. This gives you more flexibility if investment returns disappoint or if you want to work less.
• Housing security: In an economic downturn, you can cut discretionary spending, but you can't skip mortgage payments. Owning outright eliminates this risk entirely.
• Simpler estate planning: A mortgage-free home simplifies things for your estate and beneficiaries.
• Cognitive relief: One less bill to manage, one less thing to worry about as you age.

Some financial planners dismiss this as emotional decision-making. But retirement planning isn't purely about maximizing your net worth on a spreadsheet. It's about building a retirement you can actually enjoy, and for many people, that includes the peace of mind of mortgage-free homeownership.

As you're thinking about your personal retirement number, consider whether that calculation assumes you'll have ongoing housing costs or not. The answer significantly impacts how much you need saved.

The mortgage-versus-investing decision looks different at 45 than at 60.

If you're 45-50: You likely have 15-20 years until retirement. This is still enough time for investment returns to compound and for you to ride out market volatility. The case for continuing to invest (especially in KiwiSaver where you might still be receiving employer contributions) remains relatively strong, particularly if your mortgage rate is moderate.

If you're 55-60: You're entering the danger zone for sequence-of-returns risk. A market downturn in the years just before or after retirement can significantly impact your long-term outcomes. The guaranteed return from paying down your mortgage becomes more attractive. Plus, entering retirement with 5+ years still remaining on your mortgage means you'll be making those payments during your early retirement years when you're trying to establish your new financial rhythm.

If you're 60-65: Unless you're planning to work well past 65, the case for aggressively paying down the mortgage strengthens considerably. You have limited time to recover from investment losses, and starting retirement with significant debt constrains your flexibility. Many New Zealanders in this age bracket find that focusing on mortgage elimination provides both financial and psychological benefits that outweigh potential investment gains.

Understanding sequence of returns risk becomes particularly important here, as the timing of market returns matters enormously in the years around retirement.

For many New Zealanders, the answer isn't either/or. A balanced approach often makes the most sense:

Continue minimum KiwiSaver contributions: At least contribute enough to maximize any employer contributions (likely 3.5% once the increases are fully phased in). This is effectively free money you shouldn't leave on the table. Employer contributions are still part of the package even as contribution rates have increased.

Direct extra funds to mortgage payoff: Any surplus beyond your base KiwiSaver contributions goes toward accelerating mortgage repayment. This gives you the guaranteed return of your mortgage rate while still maintaining some investment growth.

Reassess as you get closer to retirement: As you move from your 40s into your 50s and 60s, you might gradually shift more toward mortgage payoff and less toward additional investing.

Consider your total financial picture: If you have other investments outside KiwiSaver (rental property, shares, business interests), you might have enough growth assets already and can focus more heavily on debt elimination.

This hybrid approach acknowledges that both goals matter: building retirement savings and eliminating debt. You're not betting everything on one strategy.

Several factors might push you more strongly toward one choice or the other:

Reasons to prioritize mortgage payoff:

• You're on a high mortgage rate that you can't easily refinance
• Your mortgage term extends past your planned retirement age
• You have health concerns that might impact your working years
• Your income is variable or uncertain
• You're a particularly anxious investor who loses sleep over market volatility
• You're already maximizing KiwiSaver and have substantial retirement savings

Reasons to prioritize continued investing:

• Your mortgage rate is relatively low (under 5%)
• You're still 15+ years from retirement
• You have very little saved in KiwiSaver or other retirement accounts
• Your income is stable and likely to increase
• You have a high risk tolerance and long investment horizon
• You're receiving employer KiwiSaver contributions that would be lost if you reduced contributions

Your specific situation, including factors like whether you have rental property or other assets, will influence which approach makes more sense.

Some financial strategies suggest maintaining your mortgage and investing your equity elsewhere, particularly in environments where mortgage rates are low. This leveraged approach can amplify returns, but it's worth understanding the risks.

In New Zealand's current rate environment (2024-2025), this strategy is less attractive than it was during the ultra-low-rate period. Borrowing at 6.5% to invest carries significant risk, especially as you approach retirement when your ability to replace losses diminishes.

There's also the practical consideration: if you're planning to retire early, potentially at 60, will you qualify for a mortgage refinancing once you're no longer earning employment income? Many retirees find it difficult to maintain or refinance mortgages once they leave full-time work, even if they have substantial assets.

Generally, leveraged investment strategies are better suited to younger investors with stable incomes and longer time horizons, not to pre-retirees in their 50s and 60s.

To make an informed decision for your situation, consider working through these questions:

• What's my current mortgage balance and interest rate?
• How many years remain on my mortgage term?
• What's my planned retirement age?
• What's my current KiwiSaver balance and contribution rate?
• Am I receiving employer contributions I'd lose if I reduced my KiwiSaver contributions?
• What's my PIR (prescribed investor rate) for KiwiSaver taxation?
• Do I have other retirement savings beyond KiwiSaver?
• How would I honestly feel about entering retirement with mortgage debt?
• Can I afford to do both (continue investing and make extra mortgage payments)?

The answers to these questions, combined with your personal risk tolerance and goals, will point you toward the approach that makes sense for your circumstances.

This article is general information only and does not constitute personalised financial advice. For advice tailored to your situation, speak with a licensed Financial Advice Provider. You can find a registered adviser at fma.govt.nz.

The mortgage-versus-investing question doesn't have a universal answer because it depends on factors that are unique to you: your specific numbers, your timeline, your temperament, and your goals for retirement.

What matters most is making an intentional choice based on understanding the trade-offs, rather than just continuing on autopilot. Whether you decide to aggressively pay down your mortgage, maximize your retirement investing, or pursue a hybrid approach, the important thing is that your strategy aligns with both your financial situation and your personal values.

For many New Zealanders approaching retirement, the answer ends up being some version of 'both', maintaining base retirement contributions while directing extra cash flow toward mortgage elimination. This balanced approach builds savings while working toward the peace of mind of mortgage-free retirement.

Whatever you decide, make sure your choice is based on your actual circumstances and goals, not just on what worked for your neighbour or what some online calculator suggested using generic assumptions.