What Is an Interest-Only Mortgage? Benefits, Risks & Key Insights

Every month, a standard mortgage payment does two things: it covers the interest owed, and it chips away at the principal balance. An interest-only mortgage strips out the second part. You pay the interest, and nothing else. The full loan balance stays exactly where it started.

This sounds alarming if you have been taught that mortgage payments should always be "building equity." And for many borrowers, an interest-only structure would be a bad fit. But for others, particularly real estate investors, self-employed borrowers in transition, and people using short-term private financing, interest-only payments can be a deliberate and practical choice. The key is understanding what you are giving up, what you are gaining, and how you plan to get out.

What Is an Interest-Only Mortgage?

An interest-only mortgage is a loan where the borrower pays only the interest charges for the duration of the term. No portion of the payment goes toward reducing the principal. At the end of the term, the borrower owes the same amount they originally borrowed, payable as a lump sum (the "balloon payment").

In Canada, interest-only mortgages are not offered by the major banks. Federal regulations from the Office of the Superintendent of Financial Institutions (OSFI) require federally regulated lenders to qualify borrowers based on amortizing payments, which effectively rules out interest-only products at the big banks and most credit unions.^[1]

Instead, interest-only mortgages in Canada are primarily available through private lenders and mortgage investment corporations (MICs). This means they come with higher interest rates than conventional bank mortgages, but also with more flexibility on qualification and structure.

How Interest-Only Payments Work

The math is straightforward. Your monthly payment is the annual interest rate divided by 12, multiplied by the outstanding principal.

On a $300,000 mortgage at 7% annual interest:

• Annual interest: $300,000 x 7% = $21,000
• Monthly payment: $21,000 / 12 = $1,750

That $1,750 covers the interest for the month. The balance stays at $300,000. After 12 months of payments, you have paid $21,000 in interest and still owe $300,000.

Compare that to the same mortgage amortized over 25 years: the monthly payment would be approximately $2,101. Of that first payment, roughly $1,750 goes to interest and $351 goes to principal. Over 12 months, you would reduce the balance by about $4,400.

The difference in monthly cash flow ($351 per month in this example) is the trade-off. Lower payments now, but no equity being built through those payments.

Interest-Only vs. Amortizing: Payment Comparison

Here is how the numbers break down on a $300,000 mortgage across different rate scenarios:

Notice that as rates increase, the monthly savings from interest-only shrink in both absolute and percentage terms. At lower rates, the amortizing payment includes a meaningful principal component. At higher rates, most of the amortizing payment is interest anyway, so the difference is smaller.

Who Offers Interest-Only Mortgages in Canada?

If you are exploring current private mortgage rates in Ontario, you will notice that virtually all private lending products are structured as interest-only. This is the norm, not the exception, in the private lending space.

When Interest-Only Mortgages Make Sense

Real estate investors maximizing cash flow

An investor buying a rental property may prefer interest-only payments to keep monthly costs low and maximize the spread between mortgage payments and rental income. If the property generates $2,200 per month in rent and the interest-only payment is $1,750, the investor has $450 in monthly cash flow (before expenses). With an amortizing payment of $2,101, that cash flow drops to $99.

The investor is betting on property appreciation and rental income rather than paying down the mortgage. Whether this is wise depends on the market, the property, and the investor's overall financial position.

Property flippers on a short timeline

Someone purchasing a property to renovate and resell within 6 to 12 months has no reason to pay down principal. They need the property financed for a short period, and the lower monthly payments during the renovation period keep carrying costs manageable. The exit strategy is the sale itself.

Self-employed borrowers in transition

A self-employed borrower who recently started a business may have limited provable income for bank qualification but strong actual earnings. An interest-only private mortgage can provide financing for 12 to 24 months while the borrower builds the income documentation needed to qualify for a conventional mortgage at renewal.

Temporary bridge to conventional financing

Borrowers who need financing quickly, perhaps due to a divorce settlement, estate distribution, or a time-sensitive purchase, sometimes use interest-only private mortgages as a short-term solution. The plan is to refinance into a bank mortgage once the immediate situation stabilizes. Having a clear exit strategy from private to bank financing is critical in this scenario.

Renovation periods

If you are buying a property that needs significant work before it can generate income or be refinanced at full value, interest-only payments keep costs low during the construction period. Once renovations are complete and the property value increases, you refinance based on the improved value.

When Interest-Only Does Not Make Sense

Interest-only is not a good fit if:

• You are buying your forever home. If you plan to live in the property for 10 or 20 years, you want to be paying down principal. An interest-only mortgage over that timeframe means paying interest indefinitely with nothing to show for it in terms of equity growth from payments.
• You have no exit plan. If you cannot articulate how and when you will pay off the principal, interest-only is a trap. The balloon payment will arrive whether you are ready or not.
• You are stretching to afford the property. If interest-only is the only way you can afford the monthly payments, the property is likely too expensive. A decline in property value or an inability to refinance at term end could leave you in a difficult position.
• You expect rates to rise significantly. If your exit strategy involves refinancing into a new interest-only mortgage, higher rates at renewal mean higher payments. Check the current rate outlook before committing.

The Balloon Payment Risk

This is the single most important thing to understand about interest-only mortgages: at the end of the term, you owe the entire principal balance in one lump sum.

On a $300,000 interest-only mortgage with a 12-month term, you will have paid $21,000 in interest over the year (at 7%). On month 13, you owe $300,000. That money has to come from somewhere.

The three most common outcomes:

1. Refinance. You take out a new mortgage (bank or private) to repay the existing one. This works if you have sufficient equity, your financial situation has improved, or the property value has increased.
2. Sell the property. The sale proceeds pay off the mortgage. This is the exit plan for flippers and some investors.
3. Renew with the existing lender. Some private lenders and MICs will renew for an additional term, subject to a review of the property value and the borrower's situation. This is not guaranteed.

The risk is what happens if none of these options work. If property values have dropped, if your income has not improved, or if lending conditions have tightened, you may not be able to refinance. In that scenario, the lender can pursue remedies including power of sale. This is not theoretical. It happens, and it is why exit strategy planning matters so much.

Exit Strategy Planning

Before signing an interest-only mortgage, you should be able to answer these questions clearly:

1. How will I repay or refinance the principal at term end? "I will figure it out later" is not a plan.
2. What is my backup if Plan A fails? If the refinance does not come through, can you sell? Do you have other assets?
3. What happens if property values decline 10% to 15%? Will you still have enough equity to refinance?
4. Am I actively working toward bank qualification? If the goal is to move to conventional financing, are you building the income documentation and credit profile the bank will need?
5. Have I budgeted for renewal fees? Private lender renewals typically involve lender fees of 1% to 2% and legal costs of $1,000 to $2,000.

A mortgage broker can help stress-test your exit strategy and identify potential problems before they become real ones. The time to discover that your refinance plan has a gap is before you sign, not 11 months into the term.^[2]

Building toward a bank mortgage

For many borrowers, an interest-only private mortgage is a temporary step. The plan is to use the private financing for 12 to 24 months while addressing whatever prevented bank qualification in the first place: building self-employment income history, improving credit, settling debts, or waiting for a probate or divorce to finalize.

If this is your situation, the interest-only structure works in your favour: it keeps carrying costs low while you focus on meeting bank qualification criteria. Just make sure the timeline is realistic. If you need two years of income documentation for bank qualification and you are taking a 12-month private mortgage, the math does not work unless you plan for a renewal.^[3]