Should You Prepay Your Mortgage or Invest? (A Simple Canadian Guide)
Prepaying Your Mortgage vs. Investing: The Simple Question
Should you use your extra cash to pay down your mortgage early, or are you better off investing it in the stock market or GICs? It is a question almost every homeowner in London, St. Thomas, and across Southwestern Ontario asks at some point.
While the financial media loves to make this topic look incredibly complicated, the math actually boils down to a few simple rules of thumb. Here is a straightforward, real-world guide to help you make the right choice for your family budget.
Rule 1: Prepayment is a Guaranteed, Tax-Free Return
When you put extra money toward your mortgage principal, you instantly stop paying interest on that portion of your debt. Because of this, prepaying your mortgage is mathematically identical to earning a guaranteed, tax-free interest rate equal to your mortgage rate.
- If your mortgage rate is 4.59%, every dollar you prepay saves you 4.59% in interest. That is a guaranteed 4.59% return on your money.
- Because mortgage interest on your home is paid with post-tax dollars, this savings is completely tax-free. You do not have to report it to the CRA, and you do not pay any capital gains tax on it.
To get that same value from a regular, taxable investment account, you would actually need to earn a much higher return—often around 7.6% or more before taxes—just to break even after paying your marginal tax rate.
Rule 2: Tax-Free Accounts (TFSAs & RRSPs) Change the Math
If you have unused contribution room in your Tax-Free Savings Account (TFSA) or Registered Retirement Savings Plan (RRSP), the choice is much simpler:
- Inside a TFSA or RRSP: Your investments grow tax-free. Therefore, the decision depends on whether you believe your investment portfolio can consistently beat your mortgage interest rate over the long run.
- The Verdict: If your mortgage rate is low (say, under 4%), long-term investing in a balanced stock index portfolio has historically outperformed. But if mortgage rates are higher (above 5%), securing a guaranteed 5% tax-free return by paying down your debt is incredibly hard to beat.
A Real-World Example in Southwestern Ontario
Let us look at a typical scenario. Imagine you have a $500,000 mortgage at 5.25% interest, and you have $10,000 in extra cash available today:
- Strategy A (Prepay Debt): You apply the $10,000 directly to your mortgage principal. You get a guaranteed 5.25% return, shaving thousands of dollars off your total lifetime interest bill and cutting months off your amortization period.
- Strategy B (Invest in GICs): You invest the $10,000 in a GIC yielding 5.10%. Since the GIC rate is lower than your mortgage rate (and is taxable if kept outside a TFSA), you are actually losing money compared to paying down your debt.
- Strategy C (Invest in the Stock Market): You invest in a stock index portfolio targeting a 7.00% return. While you might get a higher return, you also take on market volatility. If the stock market drops, your return could become negative, whereas your mortgage savings are 100% locked in.
Regional Down Payment & Equity Benchmarks
To see how this fits your local area, here is a quick look at average home values and minimum down payments across our service areas in early 2026:
| City | Average Home Value | Minimum Down Payment | Core Equity Opportunity |
|---|---|---|---|
| London | $662,000 | $41,200 | Utilize prepayment options to quickly build equity in a standard family home. |
| St. Thomas | $584,000 | $33,400 | Refinance your mortgage if you've built up high equity to pay off high-interest credit cards. |
| Woodstock | $658,000 | $40,800 | Pay down principal using annual prepayment limits (usually 10% to 20%) to save on interest. |
| Strathroy | $625,000 | $37,500 | Lock in your rates early to secure a wholesale rate-hold. |
What is the Best Choice for You?
If you prefer safety, peace of mind, and a guaranteed return, prepaying your mortgage is an outstanding strategy. If you have TFSA or RRSP room and a long-term investment horizon, investing a portion of your funds can also build wealth. Often, the best strategy is a balanced approach—doing both!
Ready to see what makes the most sense for your home and budget? Reach out to Dallas Martin today for a custom interest savings audit.
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