Breaking Early — Worth It or Not?
Ending a mortgage before its term is up almost always triggers a penalty — sometimes a modest one, sometimes a surprisingly large one. Understanding how that penalty is calculated is the difference between a smart move and an expensive one. Here's how the math really works.
Why people break a mortgage
Breaking isn't a failure — it's often a deliberate financial decision. These are the situations that bring homeowners to the question.
Rates have dropped since you locked in, and the interest you'd save over the remaining term could outweigh the cost of getting out early.
You want to tap equity, roll higher-interest debt into your mortgage, or restructure — and that means opening the existing mortgage before renewal.
You're moving and not carrying the mortgage forward. If you can't port it to the new property, the existing one has to be discharged.
Separation, a change in income, a growing family, or a need to change who's on title — circumstances shift, and the current mortgage no longer fits.
How penalties work
Your mortgage type largely determines which formula your lender uses.
The greater of two numbers
On most fixed-rate mortgages the penalty is the greater of three months' interest or the Interest Rate Differential (IRD). When rates have fallen since you signed, the IRD is usually the larger of the two — and that's where fixed penalties can climb.
Usually three months' interest
Most variable-rate mortgages charge a simpler penalty of roughly three months' interest on the balance. It's typically far more predictable and often much smaller than a fixed-rate IRD penalty.
What is the Interest Rate Differential (IRD)?
In plain terms, the IRD is the lender's estimate of the interest income they lose by letting you leave early. They compare the rate on your existing mortgage to the rate they could charge a new borrower today for a term similar to the time you have left. If your rate is higher than today's comparison rate, that gap — applied to your balance over the remaining months — is the IRD.
The catch is that every lender calculates it differently. Some compare against their posted rates rather than the discounted rate you actually pay, which can inflate the number substantially. The balance, the months remaining, and the specific comparison rate all feed the result — which is exactly why the only figure you should rely on is the one your own lender puts in writing.
Doing the break-even math
Breaking only makes sense when the money you save is bigger than the money it costs. Put both sides on the table. On the cost side: the prepayment penalty, plus any discharge fee, legal or appraisal costs, and — if you're switching lenders — potential registration or transfer charges. On the savings side: the interest you'd avoid over the remaining term by moving to a lower rate.
If the total savings clearly exceed the total costs, breaking can be worth it. If they're close, it usually isn't — the certainty of staying put wins. A useful shortcut is to work out how many months of lower payments it takes to recover the penalty; if that payback period is comfortably shorter than the time left on your term, the numbers are working in your favour.
You can model the interest side of this quickly with our mortgage calculators, then bring the exact penalty figure to the table so the comparison is real rather than a guess.
Alternatives to breaking
Sometimes you can get most of what you want without paying a penalty at all.
Moving homes? Many mortgages can be ported to the new property, carrying your existing rate and term with you and avoiding a penalty entirely — subject to requalifying.
Instead of breaking for a lower rate, some lenders will blend your current rate with today's rate and extend the term — capturing part of the savings without a full break.
If you're close to the end of your term, simply waiting until renewal lets you switch or refinance with no prepayment penalty at all. Timing can be the cheapest strategy of all.
Penalties on fixed mortgages can be large
IRD penalties on fixed-rate mortgages can reach several months' — occasionally many months' — worth of interest, and lender formulas vary widely. Never estimate the cost of breaking from a rule of thumb or an online average. Always request your lender's exact, written payout figure for your specific mortgage before you make any decision. This page is general information only — not advice or a commitment to lend. Your actual penalty, rate options and eligibility depend on your lender, your product and your full application, and the rules can change.
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