When prepayment penalty applies
You owe a prepayment penalty when you break a fixed-rate mortgage early (before the term ends) or when you prepay above your lender's annual privilege. The penalty is paid to the lender to compensate them for the interest they expected to earn. The amount depends on the calculation method, which the lender chooses. The two common methods are three months' interest and Interest Rate Differential (IRD).
Three months' interest vs IRD
Variable-rate mortgages and shorter fixed terms usually use the three months' interest method: penalty equals 90 days of interest on the current balance at your contract rate. Simple, predictable, manageable. Often $3K-$8K on a typical Fraser Valley first-time-buyer mortgage.
Five-year fixed mortgages at most major banks use the higher of three months' interest or Interest Rate Differential. IRD is the lender's calculation of "what we lose by you breaking now": the difference between your contract rate and the rate the bank could re-lend the same money at today, multiplied by the remaining term. In falling-rate environments, IRD can be very large — $15K to $25K+ on a typical Fraser Valley first-time buyer mortgage broken in year 3 of a 5-year term.
Why big-bank IRD calculations sometimes feel unfair
Big banks (RBC, TD, BMO, Scotia, CIBC) use their posted rate at origination as the basis for the IRD calculation, even though you received a discounted rate. This makes the penalty larger than the actual lost-revenue math suggests. Monoline lenders (MCAP, First National, etc.) typically use the actual contract rate, which produces smaller penalties. If you're worried about future flexibility, ask your broker about monoline options at application time.
How penalty interacts with refinancing
Refinancing mid-term triggers the penalty. Your refinance break-even calculator accounts for it. In a meaningfully falling-rate environment, the new lower rate's savings can outweigh the penalty in 18-36 months. In flat or rising rate environments, refinancing rarely makes sense.
How to use this calculator
Plug in your remaining balance, current contract rate, posted rate at origination (for big-bank IRD), and months remaining in the term. The calculator returns both the 3-months-interest amount and the IRD amount, and shows which one your lender will charge. Book a 20-minute chat with the FRIVE team before breaking a mortgage; a broker can usually verify the exact penalty with the lender.
Frequently asked questions
How is the penalty calculated for variable rates?
Almost always three months' interest at your current variable rate on the current balance. Simple math, manageable amount.
How is the penalty calculated for fixed rates?
Higher of three months' interest or Interest Rate Differential (IRD). On 5-year fixed mortgages at big banks, IRD is usually higher than 3 months' interest, especially in the first 3 years.
Can I avoid the penalty?
Three ways. First, port your mortgage to a new property (most lenders allow porting with no penalty if you're buying within 90 days of selling). Second, time the break for the last 3 months of the term (some lenders waive penalties in the final 90 days). Third, sell at term-end rather than mid-term.
Are there situations where the lender waives the penalty?
Yes. Death of the borrower (estate sales), marital breakdown (with documentation), and certain hardship situations sometimes result in penalty waivers. Each lender has its own policy.
Is the penalty tax-deductible?
Only if the mortgage was on rental property and the property continues as a rental. On a primary residence, no.
What if I'm just paying down extra principal?
Within your annual privilege (10-20% per year for most A-lenders), no penalty. Above the privilege, you'll pay a partial penalty on the excess. Our prepayment calculator models prepayment within privilege.
How does porting work?
You transfer the existing mortgage (rate, term, balance) to a new property. Most lenders require closing on the new property within 30-90 days of selling the old one. Porting avoids the penalty entirely.
Can I blend instead of breaking?
Yes. A blend-and-extend or blend-to-term reuses your existing rate weighted with today's rate on new money, avoiding the break penalty. Our blended rate calculator models the math.
What's the worst-case penalty?
Big-bank 5-year fixed mortgage broken in year 1, in a sharply falling-rate environment, with 3 years remaining on the term. IRD penalties in this scenario have reached $30K+ on first-time-buyer mortgages.
Should I get a fixed or variable for flexibility?
Variable mortgages have lower penalties (3 months' interest only), so they're more flexible. Fixed offers payment certainty. The trade-off is between flexibility and certainty. See our fixed vs variable journal post for the full discussion.
Sources
- Financial Consumer Agency of Canada — Mortgage prepayment penalties. canada.ca/fcac/prepayment-penalty
- FRIVE journal — Fixed vs variable mortgage in BC. fixed-vs-variable-mortgage-bc-2026
