If you break your mortgage early in Canada, your penalty is usually calculated one of two ways:
- Three months’ interest, or
- Interest Rate Differential (IRD).
Which one applies is set by your mortgage contract, not by a universal Canadian rule. The expensive surprises happen when homeowners assume “three months’ interest” but their lender applies IRD.
Start with one question: what does your contract allow the lender to charge?
Before you estimate anything, confirm the penalty clause in your agreement. You are looking for wording like:
- “greater of three months’ interest or IRD”
- “IRD only”
- “three months’ interest”
That single clause is the biggest driver of cost. Two borrowers with the same balance can get very different penalties if their contracts differ.
Three months’ interest: usually simpler, usually smaller
Three months’ interest is typically based on:
- the amount being prepaid,
- your contract rate,
- a three-month period.
For many variable-rate mortgages, this is the common method. It is not always cheap, but it is usually easier to predict than IRD.
What homeowners miss: if you are doing a partial prepayment, lenders generally calculate on the penalized portion only, not always the full balance.
IRD: where penalties can become large
IRD tries to estimate the lender’s lost interest when your old rate is higher than today’s comparison rate for a similar remaining term.
In practice, IRD gets larger when:
- your remaining balance is large,
- your contract rate is well above current comparison rates,
- you still have significant time left in your term.
That is why fixed-rate borrowers often see bigger penalty quotes than expected. If rates dropped since you signed, IRD can be materially higher than three months’ interest.
Fixed vs variable: the practical difference
A common pattern in Canada:
- Variable-rate mortgages: often three months’ interest.
- Fixed-rate mortgages: often IRD or the higher of IRD and three months’ interest.
This is not universal. Some products, monoline lenders, and specific contract terms handle it differently. The contract language controls.
Partial prepayments: helpful, but only inside your privileges
If your mortgage has annual lump-sum privileges, use them carefully. They can reduce or avoid penalties on the allowed amount.
But if you exceed the privilege limit, the excess is usually treated as penalized prepayment. Homeowners often assume “I made a lump-sum, so no penalty,” then get charged on the overage.
Why lender quotes change
Penalty estimates can move between your first phone call and final payout date because:
- rates changed (especially relevant for IRD),
- your payout date moved,
- daily interest kept accruing,
- admin/discharge fees were added.
So treat early estimates as planning numbers, not final settlement numbers.
The safest process before you break your mortgage
Use this sequence:
- Run an estimate so you have a rough range.
- Request a written payout statement from your lender for a specific date.
- Confirm whether the quote includes: penalty method, admin/discharge fees, and per-diem (daily) interest.
- If your date changes, request an updated payout statement.
If you are deciding between selling now, refinancing now, or waiting, this written payout figure is the number that should drive your decision.
Bottom line
Mortgage penalties in Canada are not guesswork, but they are contract-specific. Three months’ interest is usually more predictable; IRD is where costs often escalate. Use calculators to plan, but rely on your lender’s written payout statement before committing to a refinance, sale, or early discharge.