You inherit $300,000 and the first call is from your brother-in-law. He paid his mortgage off last year and thinks you should do the same. Your advisor says it depends. Your spouse wants the house clear. Three opinions, none of them based on what the numbers actually say.
The conventional play is simple: windfall arrives, mortgage disappears, sleep improves. The math most Canadians miss is that a 4.8% fixed mortgage you locked in two years ago is cheaper than almost any other capital you'll access for the rest of your working life, and paying it off trades a known low cost for an unknown higher one later.
The Guaranteed Loss Framed as Safety
Paying off a mortgage feels like a guaranteed win. You save 4.8% in interest, the psychological weight lifts, and the house is yours free and clear.
What you actually guarantee is that $300,000 of capital is now locked inside your walls. If your business needs a cash injection in nine months, or if a better property comes up, or if rates rise and your line of credit costs 7%, you're now borrowing at the higher rate to access equity you already owned. The mortgage you just paid off was a 4.8% loan. The HELOC you open to replace it will cost more, and the spread between the two is the price of feeling safe.
A Kelowna contractor paid off a $280,000 mortgage in early 2024 using an inheritance. Six months later, a commercial property became available and he needed the cash back. The HELOC rate was 6.9%. He effectively turned 4.8% debt into 6.9% debt for the privilege of six months without a mortgage payment.
The Tax-Sheltered Compound Most People Skip
Canada's TFSA contribution room for someone eligible since 2009 is approximately $109,000 in 2026. An RRSP contribution at 18% of earned income caps at $32,490 for the 2025 tax year, likely higher in 2026. If you inherit $300,000 and you haven't maxed both accounts, the first $140,000 goes there, not to the mortgage.
Inside a TFSA, a 6% return over 20 years turns $109,000 into $349,000, and none of that growth is taxed. Outside a TFSA, assuming a 40% marginal rate, the same growth is taxed down to roughly $253,000 after-tax. The $96,000 difference is larger than most mortgage interest savings over the same period.
An RRSP contribution generates an immediate tax refund. At a 45% marginal rate, a $32,000 RRSP contribution returns $14,400 within months. That refund, not the inheritance itself, can go toward the mortgage. You've now reduced your mortgage using the government's money while keeping your inheritance invested and sheltered.
Most people do it backwards: they pay the mortgage with the windfall, then contribute to their TFSA and RRSP slowly over the next decade, missing years of compounding and paying tax on growth that could have been sheltered.
When Debt Actually Is the Right Move
A mortgage is non-deductible. A business line of credit used to buy equipment, hire staff, or acquire another company often is. If you're self-employed and your business generates returns above 8%, paying off a 5% mortgage is a 3% opportunity cost every year.
The Smith Manoeuvre™ is the Canadian strategy for converting non-deductible mortgage debt into deductible investment debt. You don't pay off the mortgage, you redeploy the windfall as an investment, borrow against the investment to pay down the mortgage incrementally, and deduct the loan interest. The math works when the invested capital earns more than the borrowing cost, and the tax deduction lowers the effective rate further.
This only makes sense if you can handle the liquidity risk and the discipline required. It is not a safe default. But it is the opposite of the reflexive "pay it all off" advice, and for business owners with strong cash flow, it's often the better path.
The One Case Where Paying It Off Wins
If your mortgage rate is variable and rising, or if your income is unstable and the monthly payment is a real burden, or if the psychological cost of carrying debt is severe enough to affect decision-making, pay it off. The mathematically optimal choice is not always the right one.
But that decision should come after running the actual numbers: your mortgage rate, your TFSA and RRSP room, your business return on capital, your marginal tax rate, and the cost of accessing liquidity later. Most Canadians reach for the mortgage without calculating what the inherited money could earn elsewhere, how much tax shelter they leave untouched, or what they'll pay to borrow it back at 6.9% when they need cash again.
You inherit $300,000 and the first call is from your brother-in-law. He paid his mortgage off last year and thinks you should do the same. Your advisor says it depends. Your spouse wants the house clear. Three opinions, none of them based on what the numbers actually say.
The conventional play is simple: windfall arrives, mortgage disappears, sleep improves. The math most Canadians miss is that a 4.8% fixed mortgage you locked in two years ago is cheaper than almost any other capital you'll access for the rest of your working life, and paying it off trades a known low cost for an unknown higher one later.
The Guaranteed Loss Framed as Safety
Paying off a mortgage feels like a guaranteed win. You save 4.8% in interest, the psychological weight lifts, and the house is yours free and clear.
What you actually guarantee is that $300,000 of capital is now locked inside your walls. If your business needs a cash injection in nine months, or if a better property comes up, or if rates rise and your line of credit costs 7%, you're now borrowing at the higher rate to access equity you already owned. The mortgage you just paid off was a 4.8% loan. The HELOC you open to replace it will cost more, and the spread between the two is the price of feeling safe.
A Kelowna contractor paid off a $280,000 mortgage in early 2024 using an inheritance. Six months later, a commercial property became available and he needed the cash back. The HELOC rate was 6.9%. He effectively turned 4.8% debt into 6.9% debt for the privilege of six months without a mortgage payment.
The Tax-Sheltered Compound Most People Skip
Canada's TFSA contribution room for someone eligible since 2009 is approximately $109,000 in 2026. An RRSP contribution at 18% of earned income caps at $32,490 for the 2025 tax year, likely higher in 2026. If you inherit $300,000 and you haven't maxed both accounts, the first $140,000 goes there, not to the mortgage.
Inside a TFSA, a 6% return over 20 years turns $109,000 into $349,000, and none of that growth is taxed. Outside a TFSA, assuming a 40% marginal rate, the same growth is taxed down to roughly $253,000 after-tax. The $96,000 difference is larger than most mortgage interest savings over the same period.
An RRSP contribution generates an immediate tax refund. At a 45% marginal rate, a $32,000 RRSP contribution returns $14,400 within months. That refund, not the inheritance itself, can go toward the mortgage. You've now reduced your mortgage using the government's money while keeping your inheritance invested and sheltered.
Most people do it backwards: they pay the mortgage with the windfall, then contribute to their TFSA and RRSP slowly over the next decade, missing years of compounding and paying tax on growth that could have been sheltered.
When Debt Actually Is the Right Move
A mortgage is non-deductible. A business line of credit used to buy equipment, hire staff, or acquire another company often is. If you're self-employed and your business generates returns above 8%, paying off a 5% mortgage is a 3% opportunity cost every year.
The Smith Manoeuvre™ is the Canadian strategy for converting non-deductible mortgage debt into deductible investment debt. You don't pay off the mortgage, you redeploy the windfall as an investment, borrow against the investment to pay down the mortgage incrementally, and deduct the loan interest. The math works when the invested capital earns more than the borrowing cost, and the tax deduction lowers the effective rate further.
This only makes sense if you can handle the liquidity risk and the discipline required. It is not a safe default. But it is the opposite of the reflexive "pay it all off" advice, and for business owners with strong cash flow, it's often the better path.
The One Case Where Paying It Off Wins
If your mortgage rate is variable and rising, or if your income is unstable and the monthly payment is a real burden, or if the psychological cost of carrying debt is severe enough to affect decision-making, pay it off. The mathematically optimal choice is not always the right one.
But that decision should come after running the actual numbers: your mortgage rate, your TFSA and RRSP room, your business return on capital, your marginal tax rate, and the cost of accessing liquidity later. Most Canadians reach for the mortgage without calculating what the inherited money could earn elsewhere, how much tax shelter they leave untouched, or what they'll pay to borrow it back at 6.9% when they need cash again.
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