Should You Pay Off Your Mortgage First or Invest? The Answer Isn’t the Same for Everyone

One Decision. Two Very Different Outcomes.

Imagine you have an extra $1,000 every month. You could put it towards your mortgage and be debt-free years earlier, or you could invest it and watch it compound over time. Most financial conversations present this as a binary choice with a single correct answer.

In practice, the right decision depends on who you are, where you are in life, and what you’re trying to achieve. Both strategies have genuine merit. The question is which one — or which combination — makes sense for you.

Why Paying Off Your Mortgage Makes Sense

For many Australians, eliminating mortgage debt provides something that can’t be measured by investment returns alone: peace of mind. The psychological benefit of owning your home outright is real, and for people approaching retirement in particular, reducing fixed monthly obligations can meaningfully improve cash flow and reduce financial stress.

The question isn’t which strategy is theoretically superior. It’s which strategy, applied consistently over many years, is most likely to match your actual financial goals — because a strategy you abandon under pressure delivers less than a less-optimal strategy you maintain through volatility.

Why Investing Can Build More Wealth

Historically, diversified share markets have delivered higher long-term returns than mortgage interest rates over extended periods. The Reserve Bank of Australia and ASIC MoneySmart both note that long-term equity returns in Australia have averaged around 7–10% annually over multi-decade periods (though returns vary year to year and past performance is not a reliable indicator of future performance).

If your mortgage interest rate is, say, 6%, and your investments return an average of 8–9% over the long term, you come out ahead by investing the difference. The gap in returns, compounded over 20 or 30 years, can be significant.

But that calculation has conditions. It assumes you remain invested through market downturns. It assumes your investments actually achieve those long-term averages. It doesn’t account for tax on investment returns, or the psychological cost of watching a portfolio fall during a recession while still carrying mortgage debt.

Vanguard Australia’s research consistently shows that investor behaviour — specifically the tendency to sell during downturns and re-enter near peaks — often results in investors achieving returns significantly below what the market itself delivered. Investment returns are potential, not guaranteed. The Compound Interest Calculator at wealthlorraine.com can help you model different return scenarios with your own numbers.

The Case That Changes Everything: The Interest Rate

One factor that significantly shifts the balance between the two strategies is your mortgage interest rate relative to expected investment returns.

Five Questions Worth Asking Yourself

A Factor Many Australians Overlook: Superannuation

For Australians over 50, there is a third option that often outperforms both extra mortgage repayments and taxable investments: additional concessional contributions to superannuation.

Concessional contributions are taxed at 15% entering super — significantly lower than most Australians’ marginal tax rate. For someone on a 32.5% or 37% marginal rate, this tax advantage can make super contributions more effective than either extra mortgage repayments or taxable investing, particularly in the final decade before retirement.

The concessional contributions cap for 2025–26 is $30,000 (including employer contributions). If you have unused carry-forward amounts from previous years, you may be able to contribute more. As we explored in How Much Super Should You Have at Your Age?, this pre-retirement window is often the most tax-efficient period to accelerate super savings. The Super Calculator at wealthlorraine.com can help you model different contribution scenarios.

Could You Do Both?

Many Australians choose a combined approach. Rather than committing entirely to one strategy, they direct extra funds in a ratio that suits their situation — for example, putting 60% of available funds toward extra mortgage repayments and 40% into investments, or vice versa.

A combined approach might look like:

• Making regular additional mortgage repayments to build equity and reduce interest
• Maintaining a consistent investment contribution — through super or a managed fund
• Keeping an emergency fund separate and accessible
• Reviewing the balance between the two strategies annually as interest rates, market conditions and your circumstances change

This approach allows you to reduce debt while still participating in long-term market growth. For many households, it provides a practical balance between the certainty of debt reduction and the opportunity of investment growth — without requiring the discipline of going all-in on either strategy in every market environment.

The Cash Flow Calculator at wealthlorraine.com and the Retirement Calculator can help you model what different allocation strategies mean for your retirement picture across different time horizons.

There’s No Universal Answer

Financial decisions aren’t competitions. Someone else may achieve excellent results investing while carrying a mortgage. Another person may sleep better — and make better financial decisions overall — knowing their home is fully paid off. Both outcomes can be successful.

The best strategy is the one that helps you meet your financial goals with the confidence to stay the course. And the only way to know which one that is, is to run your own numbers — ideally with the help of a licensed financial adviser who understands your full situation.

As we discussed in The Hidden Cost of Waiting to Invest, the most expensive mistake is often not making a suboptimal choice between mortgage and investing — it’s delaying the decision and doing neither.