BMO Bank of Montreal mortgage penalty calculator.

Breaking a BMO Bank of Montreal mortgage: what the penalty really is

When you break a closed BMO Bank of Montreal fixed mortgage before maturity, BMO Bank of Montreal charges the greater of three months’ interest or the Interest Rate Differential (IRD). Three months’ interest is simple — roughly your balance times your rate, divided by four. The IRD is where BMO Bank of Montreal, like every Big-6 bank, gets expensive: it uses a posted-rate comparison. BMO Bank of Montreal takes its current posted rate for a term close to the time left on yours (we model around 6.79% for five years) and subtracts the discount you received when you signed. That lower comparison rate widens the gap against your contract rate, and the gap, prorated over the months left in your term, is what can push BMO Bank of Montreal penalties into five figures on a balance where a lender using its discounted rates would charge much less.

Why the BMO number surprises people

BMO uses posted-rate IRD on closed fixed mortgages; its Smart Fixed and Homeowner ReadiLine products carry their own break and registration rules. The penalty is largest early in the term — because IRD scales with the months remaining — and shrinks toward maturity, at which point three months’ interest eventually becomes the bigger of the two. The single most important thing to know is that the estimate above is only as good as the comparison rateBMO Bank of Montreal plugs in, and that figure is confirmed only in a written payout statement. Get one before you commit to anything.

Your exit options

You have more room than the payout statement implies. If you’re moving, port the mortgage to the new property — most BMO Bank of Montreal products allow it with no penalty. If you just want a better rate, ask BMO Bank of Montreal to blend-and-extend rather than break. Use your annual prepayment privilege to shrink the balance first. And the cleanest exit is always to wait for renewal, where there is never a penalty. If breaking still makes sense, run the figure through the refinance calculator to confirm the savings clear the penalty — then send us the payout statement and we’ll verify the real number and line up your exit across 100+ lenders.