Smith Manoeuvre explained: how to make mortgage interest tax-deductible in Canada

Is mortgage interest tax-deductible in Canada?

No, not on the home you live in. Interest on a mortgage for your own home is a personal cost, so it isn't deductible in Canada, unlike in the United States, where homeowners who itemize can deduct it.

Interest can be deductible when the borrowed money is used to earn income. Paragraph 20(1)(c) of the Income Tax Act allows a deduction for interest on borrowed money "used for the purpose of earning income from a business or property", as long as you are legally required to pay the interest and the amount is reasonable.

The CRA looks at what you used the money for, not at what kind of loan it is or what secures it. Its interest deductibility folio says that giving your home as security has no bearing on whether the interest is deductible.

Self-employed people who work from home can claim the business-use share of their mortgage interest as a home office cost. Employees can't. Our home office guide explains the split.

How does the Smith Manoeuvre work?

The Smith Manoeuvre uses each mortgage payment twice: the principal you pay off is borrowed straight back on a home equity line of credit (HELOC) and invested. Over time the mortgage shrinks, the investment line grows by the same amount, and the interest on the investment line is deductible.

1. Set up a readvanceable mortgage. This is a mortgage and a HELOC under one registration on your home. Each time you pay down principal, the HELOC limit goes up by the same amount.
2. Make your regular mortgage payment. Part of it pays interest and part pays down principal.
3. Borrow the principal back on a separate HELOC account used only for investing.
4. Invest it in a non-registered account, in investments that can pay income.
5. Pay the HELOC interest each month and keep the lender's statements.
6. Claim the interest on your return. Some people then put the refund on the mortgage, which frees up more room to re-borrow and invest.

The strategy is named after Fraser Smith, a British Columbia financial planner, whose 2002 book The Smith Manoeuvre made it widely known. Online it's often sold as "write off your mortgage", which oversells it: the mortgage interest itself never becomes deductible, the new investment loan's interest does.

How the Smith Manoeuvre plays out on a $500,000 mortgage

A mortgage pays down slowly at first, so the deductible share grows slowly. In the early years most of each payment is interest; the principal you can re-borrow only gets large near the end of the amortization.

Assumptions: a $500,000 mortgage at a 5% fixed rate for the whole 25 years, compounded semi-annually as Canadian mortgages are, with monthly payments of $2,908.02; each month's principal is re-borrowed the same month on a HELOC at 6%; the HELOC interest is paid from your own cash each month; no prepayments. These are round numbers for the arithmetic, not a forecast or a lender's rates. Worked out month by month and checked against the standard mortgage balance formula.

Three things stand out. After 10 years only about a quarter of the debt is deductible. The HELOC interest you pay out of pocket grows every year, to about $2,400 a month by year 25, on top of the mortgage payment. And when the mortgage is gone you still owe $500,000, now on the investment line, against whatever the investments are worth.

Putting the refunds back on the mortgage speeds it up. Under the same assumptions, if each year's tax refund from the HELOC interest goes on the mortgage and is re-borrowed to invest, the mortgage is gone in about 21 years at a 40.7% marginal rate and about 22 years at 28.2%, instead of 25. The total debt is still $500,000.

How much tax does the Smith Manoeuvre save?

The tax saved each year is the deductible interest times your marginal tax rate. On $100,000 borrowed at 6%, the interest is $6,000 a year; at a 40% marginal rate the deduction cuts your tax by $2,400, so the loan costs you $3,600 after tax, about 3.6%.

Your marginal rate depends on your income and province. Here is the same $6,000 of interest in BC and Alberta at 2026 rates, for someone whose income is a salary:

Worked out with Finvo's 2026 tax engine, the one behind the income tax calculator: federal plus provincial income tax on employment income, with the basic credits. Your own rate changes with other income and deductions.

That is the bet in one line: after tax, the investments have to earn more than the loan costs after tax. If the investments earn 3% after tax and the loan costs 4.3% after tax, you are paying to borrow. The tax deduction lowers the cost of borrowing; it doesn't make the investments any safer.

Is HELOC interest tax-deductible?

HELOC interest is deductible only for the part of the line used to earn income. A HELOC is just a loan: borrow from it to invest in a non-registered account, a rental or a business and that interest generally qualifies; borrow from it for a renovation, a car or a holiday and that interest doesn't.

When one line is used for both, only the eligible share is deductible, and the CRA won't let you choose which part your repayments reduce. Its folio gives the example of a $100,000 line, $60,000 used personally and $40,000 to invest: 40% of the interest qualifies, and after a $20,000 repayment the deductible part is 40% of the remaining $80,000, or $32,000. That is why the Smith Manoeuvre uses a separate HELOC account for investing only.

Is the Smith Manoeuvre legal? Does the CRA allow it?

Yes. Rearranging your borrowing so that the money you borrow is used to invest is allowed, as long as you can trace each dollar of the loan to an eligible use. The CRA's own interest deductibility folio says a taxpayer "may restructure borrowings and the ownership of assets to meet the direct use test."

Two Supreme Court of Canada cases set this out. In Singleton (2001), a lawyer took his capital out of his firm to buy a house and borrowed to put the same amount back; the interest was deductible because the borrowed money was used directly in the business. In Lipson (2009), the court accepted that similar steps to make home-related interest deductible were consistent with paragraph 20(1)(c), but applied the general anti-avoidance rule (GAAR) because the plan also used the spousal attribution rules to move the deduction to the higher-income spouse.

The lesson from Lipson: the plain Smith Manoeuvre, in your own name, with traceable borrowing and income-producing investments, is a recognised way to borrow to invest. Layering other tax rules on top, such as shifting income or deductions between spouses, is where the GAAR risk starts.

The investments must be able to earn income

The CRA's line 22100 page says: "If the only earnings your investment can produce are capital gains, you cannot claim the interest you paid." The test is whether you had a reasonable expectation of income, such as dividends or interest, when you bought the investment; it doesn't have to pay a set amount every year, and the income doesn't have to exceed the interest.

For common shares the CRA's position is generous: it generally considers interest on money borrowed to buy common shares deductible, because there is usually a reasonable expectation of dividends. The exception is a company that has said it won't pay dividends, so that shareholders can only profit by selling. Something that can only rise or fall in price, such as gold bullion, doesn't meet the test.

What can go wrong?

• Markets fall. The investments can drop, sometimes for years, while the loan stays the same. A 30% fall on $200,000 of investments leaves $140,000 against a $200,000 loan.
• Rates rise. HELOC rates float with prime. Between March 2022 and July 2023 the Bank of Canada raised its policy rate from 0.25% to 5%, and the big banks' prime rate went from 2.45% to 7.20%. For many borrowers, the interest on the same HELOC balance more than doubled.
• Your cash flow gets tight. You pay the HELOC interest every month on top of the mortgage, and the amount grows each year. A job loss or a pay cut makes that harder.
• You stay in debt longer. The mortgage disappears, but the investment loan doesn't. Paying it off means selling investments, possibly with capital gains tax.
• Behaviour. Selling in a panic locks in losses. Dipping into the line for personal spending taints the deduction.
• The lender or the rules change. A lender can lower a HELOC limit or call the line, and federal rules cap the revolving part of a home equity line at 65% of the home's value. Tax rules and rates can change too.

Is the Smith Manoeuvre worth it?

It can be, for a narrow group of people, and it depends far more on the investments than on the tax. The deduction only lowers the cost of borrowing; the result comes from whether the investments beat that cost over many years.

Done carelessly, it is leveraged investing with extra paperwork.

Smith Manoeuvre vs paying down the mortgage

Paying down the mortgage gives a certain, tax-free return equal to your mortgage rate; the Smith Manoeuvre swaps that certainty for the chance of a higher investment return. Every dollar of mortgage you pay off saves interest at your mortgage rate with no risk. Every dollar you re-borrow and invest has to beat the HELOC's after-tax cost, which is usually higher than the mortgage rate before tax.

With a 5% mortgage and a 6% HELOC, the investments need to earn more than about 3.6% to 4.3% a year after tax (the table above) just to break even. Paying down the mortgage also leaves you debt-free sooner; the Smith Manoeuvre leaves you with a portfolio and a matching loan.

Smith Manoeuvre vs RRSP or TFSA first

For many people, filling registered accounts comes first, because their growth is sheltered without any borrowing risk. Interest on money borrowed to contribute to an RRSP, TFSA, FHSA, RESP or RDSP is never deductible, so the Smith Manoeuvre only works with a non-registered account.

An RRSP gives a deduction on the contribution itself; a TFSA's growth is tax-free; a non-registered account pays tax on dividends, interest and gains every year. Someone with unused room usually compares those first. Our guides on RRSP vs TFSA, RRSP loans and TFSA mistakes cover the registered side, and the RRSP tax savings calculator shows what a contribution does to your tax.

Does the Smith Manoeuvre work in BC and Alberta?

Yes. The interest deduction is federal, and BC and Alberta both follow it, so the deduction lowers federal and provincial tax at your combined marginal rate. What differs is the rate: at a $100,000 salary in 2026 it is 28.2% in BC and 30.5% in Alberta; at $150,000 it is 40.7% in BC and 36.0% in Alberta.

Our BC vs Alberta income tax guide has the marginal rates from $50,000 to $150,000. Quebec has its own rules for investment expenses on the Quebec return; this guide covers BC and Alberta.

What records do I need?

You need to be able to show, for every dollar of the investment line, that it went straight into investments that can earn income. The onus is on you, not the CRA.

• The yearly interest statement from your lender for the investment HELOC.
• Monthly HELOC statements showing each advance going straight to the investment account.
• Investment account statements showing the deposits and the purchases, and the T3 and T5 slips for the income.
• A simple log: date, amount borrowed, what it bought. It answers a CRA question in minutes.
• Records of any sales, and of what you did with the money, because the CRA looks at the current use of borrowed money, not just the first one.

Keep them for at least six years after the tax year they relate to, and for as long as the loan is outstanding.

How do I claim it on my tax return?

Claim the interest on line 22100, "Carrying charges, interest expenses and other expenses", of your T1 return for the year you paid it. Add other eligible carrying charges, such as fees to manage a non-registered investment account. If you also earn foreign investment income, the line 22100 chart on the Federal Worksheet splits the charges.

Interest used for a rental goes on your rental statement (Form T776) instead, and interest used for a business on Form T2125, against that income. The rental income calculator shows what rental interest does to your net rent.

If you sell investments bought with the loan and keep the money for yourself, the matching part of the loan stops being deductible from then on. If you sell and reinvest the money straight away, the loan keeps its link.

Debt swap and cash damming

The debt swap

A debt swap is the fast version: you sell non-registered investments you already own, put the money on the mortgage, re-borrow the same amount and buy investments again. One step turns that much mortgage debt into deductible investment debt.

Selling is a disposition for tax, so any capital gain is taxable that year (half of it is included in income in 2026), and our capital gains guide explains how. If you sell at a loss and you, your spouse or another person affiliated with you buys the same or identical property within 30 days before or after the sale, the superficial loss rule denies the loss; it is added to the cost of the new purchase instead.

Cash damming

Cash damming is for business owners and landlords. Business or rental income goes into one account and is used to pay down the mortgage; the business or rental expenses are paid with money borrowed on a separate line. Because that borrowing pays expenses of earning income, its interest is deductible, while the mortgage on your home shrinks faster.

The CRA's folio accepts this: taxpayers may keep borrowed money in separate accounts from other funds, such as business receipts, which makes the tracing easier. It works only with real business or rental expenses and clean books, so each expense can be traced to the borrowed line. Employees with no business or rental have no expenses to dam.

Common mistakes

• Mixing personal spending into the investment HELOC, which makes only a share of the interest deductible and turns every repayment into a pro-rata calculation.
• Investing through a registered account, such as an RRSP or TFSA, with borrowed money. That interest is never deductible.
• Buying something that can only produce capital gains, such as gold bullion or shares of a company that has said it won't pay dividends.
• Taking the investments' dividends as spending money and then borrowing more to cover the HELOC interest without a plan. It grows the debt, and the records get harder to follow.
• Selling investments and keeping the cash, which breaks the link for that part of the loan.
• Forgetting the prepayment limits of a fixed-rate mortgage on a lump-sum paydown.
• Not claiming the interest at all, or claiming the whole line when part of it was personal.

This guide is general information for people in BC and Alberta about the 2026 tax year, checked against the Income Tax Act and the CRA's pages on 5 Nov 2026. Rules have exceptions and can change; it isn't tax, investment, legal or borrowing advice for your situation.