IRD mortgage penalty in Canada, lender by lender (2026)

By Omar M.S. Hamed, founder, O.MS.H Media Inc., Ancaster ON. Published April 28, 2026. The Interest Rate Differential, decoded. With a working calculator, lender-by-lender methodology, and worked examples for the 2026 rising-rate cycle.

If you have a fixed-rate Canadian mortgage and you are considering breaking it before maturity, the Interest Rate Differential is the number you need to understand before anything else. It is the single most expensive line item on the cost of breaking, and it is the one most articles and most lender call-centre representatives explain in a way that is not quite accurate.

Two things to know up front, both verified against lender standard charge terms and against the Financial Consumer Agency of Canada's published guidance.

One: every fixed-rate Canadian mortgage has two penalty calculations running in parallel. The actual penalty is the larger of them. The first is the three-months-interest floor. The second is the IRD calculation. Most readers know the first exists. Many do not realise the second is bounded below by the first, which means in a rising-rate cycle the two collapse to the same number.

Two: the way IRD is computed varies materially by lender, and the difference is often in the thousands of dollars when IRD is the binding constraint. The Big Six use posted-rate methodology with a discount-margin reduction. Most credit unions and monoline lenders use contract-rate methodology. The same file can produce a $9,000 penalty at one and a $4,000 penalty at the other.

The page below works through both points with the math, the calculator, and the lender-by-lender table, written for a reader staring at a renewal letter or a mid-term break decision.

The cycle direction is the unlock

IRD only produces a meaningful penalty when the comparison rate the lender uses is materially below your contract rate. That condition is met in falling-rate cycles, when you locked at a high rate and rates have since fallen. The lender claws back the spread between what you committed to pay and what they could re-lend the money at today.

In rising-rate cycles, the condition is not met. You locked at a low rate, rates have since risen, and the differential between your contract rate and the lender's current comparison rate is zero or negative. The IRD calculation returns zero. The three-months-interest floor governs.

For Canadian borrowers maturing in 2026 with contract rates from 2020 to 2022 (typically 1.5 to 2.5 per cent) facing current market rates of 4 to 5 per cent, the cycle direction is unambiguously rising. The penalty defaults to the floor for almost every file in this cohort, regardless of which lender you are with. Lender-by-lender method matters less than the cycle direction.

This is the single most important thing to know before reading any further. If your contract rate is below current market, the floor is your answer. The rest of the page is about the case where it is not, plus the worked floor calculation for the case where it is.

The three-months-interest floor

The floor is the minimum penalty for a fixed-rate Canadian mortgage. Multiply your current balance by your contract rate, divide by 12, multiply by 3.

On a $400,000 balance at a 1.79 per cent contract rate, that arithmetic is: $400,000 × 0.0179 ÷ 12 × 3 = $1,790. That is the floor. In a rising-rate cycle, that is also the answer.

The floor exists because lenders need an administrative fee threshold for breaking a contract that does not depend on rate movements. Variable-rate mortgages typically use only the three-months-interest method (no IRD), so for variable holders the floor is always the answer regardless of cycle direction.

How the Big Six compute IRD: posted-rate methodology

RBC, TD, Scotiabank, BMO, CIBC, and National Bank all use posted-rate IRD with a discount-margin reduction. The computation has three inputs.

First, the lender's posted rate at the time you signed your current term. This is not what you actually paid; it is the lender's published five-year fixed rate on the day your mortgage started. Posted rates are generally 100 to 200 basis points above what well-qualified borrowers actually receive. As of late April 2026, Big Six posted five-year rates run roughly 5.79 to 6.79 per cent, well above current discounted offers around 4.29 to 4.94 per cent.

Second, the discount margin you received at origination. If your posted rate at signing was 4.79 per cent and your contract rate was 1.79 per cent, your discount margin was 3.00 per cent. The lender takes the discount margin as a fixed reduction on the comparison rate.

Third, the lender's current posted rate for a term equal to your remaining months. If you have 18 months left, the lender uses their current posted rate for the closest available term (often the two-year posted rate, or a calculated rate via interpolation). Apply your discount margin reduction to this comparison.

The IRD differential is then your contract rate minus the discounted comparison rate. If positive, multiply by remaining balance and divide by 12, multiply by remaining months. If zero or negative, the floor governs.

The discount-margin reduction is the part most readers find counterintuitive. The lender uses your old discount margin against their new posted rate, which can produce a comparison rate that does not match any rate available in the market. In falling-rate cycles, this widens the differential and increases the penalty. In rising-rate cycles, it does not help the borrower; the IRD is already zero before this step matters.

Lender standard charge terms documenting this methodology are filed in provincial land registries and are also available through each lender's mortgage information request channel. RBC, BMO, and CIBC publish methodology summaries on their consumer-facing FAQ pages; TD, Scotia, and NBC tend to provide them on request rather than on the website. The mechanic is the same across all six.

How most credit unions and monoline lenders compute IRD: contract-rate methodology

Most credit unions, MCAP, MERIX, Strive, First National, Equitable Bank, Home Trust, and B2B Bank use contract-rate IRD. Two inputs.

First, your actual contract rate (not posted rate, not posted-minus-discount).

Second, the lender's current discounted rate for a term equal to your remaining months.

The IRD differential is the contract rate minus the current discounted rate. Apply to balance over remaining months as above.

Because the comparison rate is the current discounted rate (not the posted rate minus your old discount margin), the differential tends to be smaller in falling-rate cycles than under the Big Six method. On a typical falling-rate file, the contract-rate computation produces a penalty roughly 30 to 60 per cent lower than the posted-rate computation, depending on the size of the original discount margin.

In rising-rate cycles, the contract-rate method also returns zero or negative, so the floor governs at credit unions and monolines just as it does at the Big Six.

IRD penalty calculator

Enter your file inputs. The calculator returns the three-months-interest floor, the IRD computation under your selected lender's methodology, and the actual penalty (the larger of the two).

Worked examples for 2026 conditions

Four representative files spanning the cohort that is breaking, switching, or refinancing in 2026. Every number is reproducible by entering the inputs into the calculator above.

File 1: $400K balance, 1.79 per cent, 18 months remaining (Big Six)

Floor: $1,790. IRD: posted-rate method against the Big Six's current posted rate of roughly 6.09 per cent for a two-year term, less your 3.00 per cent original discount margin, gives a comparison of 3.09 per cent. Your contract rate is 1.79 per cent, comparison is 3.09 per cent, differential is negative 1.30 per cent. IRD returns zero. Actual penalty: $1,790.

File 2: $400K balance, 1.79 per cent, 18 months remaining (monoline)

Floor: $1,790. IRD: contract-rate method, your 1.79 per cent versus current discounted 4.39 per cent. Differential is negative 2.60 per cent. IRD returns zero. Actual penalty: $1,790. Same answer as the Big Six file in this rate cycle.

File 3: $300K balance, 5.49 per cent, 24 months remaining (Big Six, falling-rate counterfactual)

Hypothetical to show what posted-rate IRD looks like when it does apply: contract 5.49 per cent, discount margin 0.50 per cent on origination, current comparison rate 3.79 per cent. Differential 5.49 minus 3.29 = 2.20 per cent. Apply to $300K over 24 months: $300,000 × 0.022 × 24 ÷ 12 = $13,200. Floor: $300,000 × 0.0549 ÷ 12 × 3 = $4,118. Larger is IRD. Actual penalty: $13,200. This is the file Big Six posted-rate methodology was designed for.

File 4: same as File 3, but at a credit union or monoline

Contract-rate method: 5.49 per cent versus current discounted 3.79 per cent. Differential 1.70 per cent (smaller because no discount-margin reduction inflating it). Apply to $300K over 24 months: $300,000 × 0.017 × 24 ÷ 12 = $10,200. Floor: $4,118. Actual penalty: $10,200. About $3,000 less than the Big Six for the identical file.

Lender-by-lender quick reference

Methodology summary as of late April 2026. Verify against your specific contract; lenders occasionally update their standard charge terms.

What to do next

1. Phone or email your current lender and request, in writing, your current prepayment penalty if you broke today. They are required to provide the number under FCAC consumer-protection rules.
2. Confirm whether your lender uses posted-rate or contract-rate methodology against the table above.
3. Run the calculator with your inputs to verify the lender's quoted number is correct. If they differ by more than $50, ask the lender to walk you through the computation.
4. If the penalty is the floor (rising-rate cycle), the IRD detail does not change your decision. Move on to the rate-spread and use-of-funds questions in the refinance four-question framework.

A note on whose advice to trust on this

The methodology above is sourced from lender standard charge terms and FCAC consumer-protection guidance. The math is reproducible. What I cannot give you is an authoritative quote on your specific file; only your lender can. For an independent broker review of your full file, including the IRD quote against current best-rate offers, Homewise (FSRA #12984) is a Canadian licensed brokerage that quotes multiple lenders online. RenewalRate.ca earns a commission on funded mortgages routed through Homewise.

Sources

• FCAC: Breaking your mortgage contract
• FCAC: The cost of paying off your mortgage early
• Interest Act, s. 6 (Canadian semi-annual compounding rule)
• Bank of Canada: Posted interest rates offered by chartered banks
• Ratehub: Current best Canadian mortgage rates
• Ratehub: Big bank posted and discounted rates
• Lender standard charge terms (RBC, TD, BMO, CIBC, Scotiabank, NBC, MCAP, First National, Equitable Bank). Filed in provincial land registries; available from the lender on request.

About the author. Omar M.S. Hamed is the founder of O.MS.H Media Inc. (operating as ohms.marketing), a performance marketing firm in Ancaster, Ontario. He is not a licensed mortgage broker. The framework above is sourced from primary regulatory and lender documentation; for a recommendation on your specific file, consult a FSRA-licensed mortgage agent. LinkedIn.