Breaking your mortgage early is one of those decisions that sounds simple until you’re actually looking at the numbers. I get calls about this regularly — usually from clients who’ve seen rates move and are wondering if they should get out of their current term and lock into something better. Sometimes the answer is yes. Often it isn’t. And the difference comes down to math that most people haven’t been shown how to do.
Key Takeaways
- Variable rate penalty = 3 months interest; fixed rate = greater of 3 months or IRD
- Big banks use posted rates in IRD calculations — penalties are often much higher than expected
- The key question: do savings over the remaining term exceed the penalty cost?
- Always get your exact penalty number in writing before making any decisions
Here’s how I think about it.
First, Understand What Penalty You’re Actually Facing
The penalty for breaking your mortgage depends on whether you’re in a fixed or variable rate.
Variable rate: straightforward. The penalty is typically three months of interest on your outstanding balance. On a $500,000 mortgage at 5%, that’s roughly $6,250. Painful, but knowable.
Fixed rate: more complicated. Lenders charge the greater of three months’ interest or an Interest Rate Differential (IRD) penalty. The IRD is calculated based on the difference between your contract rate and the rate the lender can offer today for the remaining term — essentially, they’re charging you for the profit they’ll lose by letting you out early.
When rates have risen since you locked in, your IRD tends to be low or zero — the lender can re-lend that money at a higher rate, so there’s less to compensate for. When rates have fallen, the IRD can be substantial. We’re talking $15,000 to $30,000 or more on a typical mortgage. I’ve seen higher.
The Big Bank Problem
Here’s something worth knowing: not all IRD formulas are created equal. The big banks use their posted rates — not the discounted rates most people actually receive — in their IRD calculation. That methodology tends to produce significantly higher penalties than you’d get with a monoline lender or credit union. It’s not illegal. It’s just opaque, and it catches people off guard.
If you’re with a major bank and you’re thinking about breaking, get the actual penalty number in writing before you do anything else. Don’t estimate it yourself.
The Break-Even Calculation
The core question is simple: will the interest savings over the remaining term exceed the penalty you’ll pay to get out?
If you have three years left on your term and you’d save $200/month by switching to a lower rate, that’s $7,200 in savings. If your penalty is $9,000, you’re underwater — you don’t break even until month 45, and your term is only 36 months long. It doesn’t make sense.
Flip that scenario: two years left, $400/month in savings, $5,000 penalty. You break even at month 12.5 and come out ahead by $4,600 over the term. That’s worth a conversation.
The calculation changes with every deal, and it also changes if you’re planning to blend and extend with your existing lender rather than break and move. Sometimes blending is the better path. Sometimes it’s how lenders obscure the true cost of keeping you.
When Life Forces the Decision
Sometimes breaking early isn’t about chasing a lower rate — it’s about life. Selling the home. Divorce. A job relocation. In those cases, the question isn’t whether the math works over the term — it’s just about minimizing the cost of getting out.
If you know a life event is coming, the timing of when you break can affect your penalty significantly. Earlier in a rising-rate environment often means a lower IRD. Getting ahead of the decision by even a few months can make a real difference.
The Current Environment
We’ve been in a falling-rate cycle. The Bank of Canada has been cutting. That means for anyone who locked into a fixed rate 18–24 months ago at a higher rate, the IRD calculation right now could actually be working in your favour — your rate is higher than what’s available today, but the spread may have narrowed enough that the penalty is manageable.
That’s exactly the scenario worth modeling. If you locked in at 5.5% two or three years ago and there’s time left on your term, it’s worth running the numbers to see if breaking and refinancing at today’s rates makes financial sense before rates potentially move in the other direction.
Don’t Guess at This
The math on breaking a mortgage looks straightforward until you’re actually trying to get the right penalty number out of a bank, account for the blend-and-extend option, model the true cost of the new rate over the remaining term, and figure out whether the timing makes sense given where rates might go.
This is exactly the kind of analysis I do with clients. It doesn’t take long, and it either confirms you should stay put or gives you a clear picture of what moving actually costs and saves. Either way, you make the decision with real numbers in front of you instead of a guess.
If you’re wondering whether breaking your mortgage makes sense right now, let’s run it.
Ready to run the numbers on your situation?
Every mortgage decision is different. Let’s look at yours together — no obligation, just straight talk.
