In Canada, the terms “adjustable-rate mortgage” and “variable-rate mortgage” are often used interchangeably, but they describe two different products. The distinction matters — especially when interest rates are volatile.
An adjustable-rate mortgage (ARM) is one of several mortgage types available in Canada — compare it to fixed and variable options before deciding.
ARM vs VRM: the key difference
Both adjustable-rate mortgages (ARMs) and variable-rate mortgages (VRMs) have rates that float with the lender’s prime rate. The difference is what happens to your payment when rates change.
| Feature | Adjustable-Rate Mortgage (ARM) | Variable-Rate Mortgage (VRM) |
|---|---|---|
| Rate | Moves with prime | Moves with prime |
| Payment amount | Changes when prime changes | Stays the same |
| Principal vs interest split | Always paying down principal | Split shifts — less principal when rates rise |
| Trigger rate risk | None — payment always adjusts | Yes — if rates rise enough, payment may not cover interest |
| Negative amortization risk | None | Yes — can occur if trigger rate is hit |
| Payment predictability | Lower — amount changes | Higher — amount stays constant |
| Cash flow planning | Harder to budget | Easier to budget |
How an ARM works
With an adjustable-rate mortgage, every time the Bank of Canada changes the overnight rate and your lender adjusts their prime rate, your mortgage payment changes proportionally.
Example: $500,000 ARM at prime − 0.50%, 25-year amortization
| Bank of Canada Move | Prime Rate | Your Rate | Monthly Payment | Change |
|---|---|---|---|---|
| Starting point | 4.50% | 4.00% | $2,622 | — |
| +0.25% rate hike | 4.75% | 4.25% | $2,696 | +$74 |
| +0.25% rate hike | 5.00% | 4.50% | $2,771 | +$75 |
| −0.25% rate cut | 4.75% | 4.25% | $2,696 | −$75 |
| −0.50% rate cut | 4.25% | 3.75% | $2,548 | −$148 |
Each payment is recalculated to ensure you pay off the full mortgage within the original amortization period. You never fall behind on principal.
How a VRM works (and the trigger rate problem)
With a variable-rate mortgage, your payment stays the same but the allocation between principal and interest shifts.
Example: $500,000 VRM at prime − 0.50%, fixed payment of $2,622
| Prime Rate | Your Rate | Interest Portion | Principal Portion | Status |
|---|---|---|---|---|
| 4.50% | 4.00% | $1,653 | $969 | Normal — paying down principal |
| 5.00% | 4.50% | $1,860 | $762 | Less principal each payment |
| 5.50% | 5.00% | $2,068 | $554 | Much less principal |
| 6.20% | 5.70% | $2,622 | $0 | Trigger rate — payment covers only interest |
| 6.50% | 6.00% | $2,746 | −$124 | Negative amortization — balance grows |
The trigger rate is the point where your fixed payment no longer covers the interest. Beyond that point, unpaid interest is added to your principal.
Who should choose an ARM
An adjustable-rate mortgage is better if you:
- Want transparency — You always know your payment covers principal and interest
- Can handle payment variability — Your budget has room for payments to increase
- Want to avoid trigger rate risk — ARMs cannot hit a trigger rate because the payment always adjusts
- Are in a declining rate environment — Your payments decrease automatically as rates drop
- Have a high risk tolerance — You are comfortable with rate uncertainty
Who should choose a VRM
A variable-rate mortgage with fixed payments is better if you:
- Need payment stability — You want to know exactly what your payment is each month for budgeting
- Are close to the edge of affordability — A payment increase could strain your finances
- Expect a short rate-increase cycle — If rates rise temporarily and then drop, the VRM smooths out the short-term impact
- Are disciplined about prepayments — If rates are low and less of your payment goes to interest, you can make lump-sum prepayments to compensate
Canadian ARMs vs American ARMs
The products are quite different:
| Feature | Canadian ARM | American ARM |
|---|---|---|
| Rate adjustment | Moves with prime, changes can happen any time the BoC moves | Adjusts at set intervals (e.g., annually after an initial fixed period) |
| Initial fixed period | None — rate is variable from day one | Common — “5/1 ARM” means 5 years fixed, then annual adjustments |
| Rate caps | No formal caps — moves with prime | Periodic caps (e.g., 2% per adjustment) and lifetime caps (e.g., 5% total) |
| Negative amortization | Not possible (payment adjusts) | Possible with some ARM structures |
| Term length | Typically 5 years (then renewal) | Up to 30 years |
| Prepayment | Penalty is usually 3 months interest | May have prepayment penalties depending on product |
Canadian ARMs are simpler: the rate moves with prime, and the payment adjusts immediately. There is no teaser rate period or complex adjustment schedules.
Rate discount: ARM vs fixed
Variable/adjustable rates have historically been lower than fixed rates in Canada because the borrower assumes rate risk. The typical discount varies by market conditions:
| Market Condition | Variable/ARM Rate vs 5-Year Fixed |
|---|---|
| Normal yield curve | 0.50% to 1.50% below fixed |
| Flat/inverted yield curve | Similar to fixed or even higher |
| BoC cutting cycle | Widens — variable becomes much cheaper |
| BoC hiking cycle | Narrows or inverts — variable may exceed fixed |
In April 2026, with the Bank of Canada having cut rates from the 2023 peak, variable and adjustable rates are generally competitive with or slightly below 5-year fixed rates.
What to ask your lender
Before choosing a variable-rate product, ask these specific questions:
- Is this an adjustable-rate (payment changes) or variable-rate (payment stays the same)? — The terminology is not standardized. Confirm which type you are getting
- What is the prime rate discount or premium? — Know whether you are getting prime minus 0.50%, prime minus 1.00%, etc.
- Is the discount guaranteed for the full term? — Some lenders can change the spread in certain conditions
- What happens if I hit the trigger rate (VRM only)? — Will they increase your payment automatically, or will you go into negative amortization?
- What is the prepayment penalty? — Variable/adjustable rate penalties are typically 3 months interest, but confirm
- Can I convert to fixed mid-term? — Most variable products allow conversion to a fixed rate, but the rate offered may not be the lender’s best rate
The bottom line
In Canada, the choice between an ARM and a VRM comes down to payment predictability vs transparency. ARMs protect you from trigger-rate surprises by adjusting your payment immediately. VRMs give you payment stability at the risk of falling behind on principal. If you choose variable, make sure you know exactly which product your lender is offering — and plan for the possibility that rates move against you.