Two rates land on your desk for the same $500,000 mortgage. One is 4.59%. The other is 5.10%. That half-point gap is worth roughly $13,000 in interest across a five-year term, so most borrowers grab the lower number without looking past it. That lower number almost always belongs to a closed mortgage.
Closed mortgages are the default product at nearly every lender. The rate is better, the payments are predictable, and the majority of borrowers never need to break the contract. The pain, when it arrives, is concentrated in a small clause about prepayment penalties that most people skim past at signing.
What Actually Makes a Mortgage “Closed”
A closed mortgage locks three things in place for the length of your term: the interest rate, the payment schedule, and the amortization. In return, the lender gives you a discount, usually somewhere between 0.15% and 0.75% below the open-mortgage rate on the same product.
The restrictions are the flip side. You can’t pay the full balance off, renegotiate the rate, or move to another lender mid-term without paying a penalty. Limited extra payments are normally allowed, but there’s a cap.
And the term is not the same as the amortization. A five-year closed term on a 25-year amortization means you’re committed for those five years, after which you renew. That distinction trips up a surprising number of first-time buyers.
Closed vs. Open: A Straight Trade-Off
If you want the ability to clear the balance whenever you like, an open mortgage gives it to you, at a rate often a full percentage point higher. On a $400,000 balance, that gap runs about $4,000 a year. Flexibility has a price tag, and it’s printed clearly.
Closed wins for most people. You aren’t planning to sell in fourteen months, you don’t have an inheritance landing next spring, and you’d rather bank the savings. The risk is that a five-year plan and a five-year mortgage don’t always stay aligned.
The Penalty Is Where the Story Turns
Break a closed mortgage early and you owe a prepayment penalty. Lenders calculate it two ways and charge you whichever is higher. That single detail is responsible for most of the horror stories.
Three months’ interest
The friendlier formula: balance × rate ÷ 12 × 3. On a $400,000 balance at 4.5%, you’re looking at roughly $4,500. Unpleasant, but manageable.
Interest rate differential (IRD)
This one is based on the gap between your rate and the lender’s current rate for a comparable term, multiplied by the months left. When rates have fallen since you signed, the result is brutal.
Picture a 5.29% rate with 38 months remaining, while the lender now posts 3.99%. That 1.3% spread across three-plus years of a $400,000 balance can push the penalty past $16,000. After the rate spikes and drops of the past few years, some borrowers have stared down IRD penalties north of $25,000, which is more than the equity they’d built.
That figure decides whether selling, refinancing, or consolidating debt makes financial sense. It’s also the one number almost nobody asks about before signing.
When a Closed Mortgage Is the Right Call
- You’re staying put. Five years in the same home is the baseline assumption, and for most owners it holds.
- You want the lowest rate available. Closed products reliably undercut open ones.
- Your income is stable and you have no windfall on the horizon you’d want to throw at the principal.
- The prepayment limits suit you. Most closed mortgages allow 10% to 20% of the original balance in annual lump sums, plus doubled-up payments, which is plenty of room for the average household.
- You’d rather not renegotiate mid-term. A closed contract runs its course with no decisions required.
Escape Routes Built Into the Contract
You aren’t fully boxed in. Lenders leave a few doors open, and knowing them can save five figures.
Porting
Sell your home and buy another, and most closed mortgages let you carry the rate and balance across, as long as both deals close with the same lender inside a window of typically 30 to 120 days. It’s the cleanest way to avoid a penalty during a move.
Blend and extend
Need more money before maturity? Lenders can blend your existing rate with today’s posted rate and give you a weighted average on the combined amount, penalty-free. Handy when you’re renovating or topping up.
Prepayment privileges
Annual lump sums, increased regular payments, and one-time payment boosts all chip away at the principal without triggering charges. Used consistently over a five-year term, they can knock years off the amortization.
Assumable terms
Some closed mortgages are assumable, which means a buyer can take over your loan and your rate when you sell. If you’re sitting at 2.4% and current rates are near 6%, that feature is genuinely valuable, and worth confirming before you list. An assumable mortgage can turn a slow listing into a quick sale.
Alternatives When the Bank Won’t Bend
Sometimes a closed mortgage simply won’t stretch to fit. Private arrangements occasionally fill the gap. A wraparound mortgage, for instance, lets a seller carry a second loan that wraps around your existing one, effectively becoming your lender. Rates run higher and the paperwork takes patience, but it works when a penalty would otherwise kill the deal.
Property Type Quietly Changes the Terms
Not every closed mortgage is priced the same, because not every property carries the same risk. A detached house in a stable neighbourhood is straightforward. A downtown high-rise unit is not, especially if the building has a high investor-to-owner ratio or a thin reserve fund, and lenders often respond with tighter conditions or a rate premium. Getting a condo mortgage approved means clearing both your own file and the building’s.
Add rental units and the rules shift again. Properties with one to four units can still qualify for residential financing rather than commercial, provided you occupy one of them. A fourplex mortgage sits right on that line, and the rental income can offset a meaningful chunk of the carrying cost, which changes how much closed mortgage you can comfortably afford.
What to Ask Before You Sign
The contract is negotiable in more places than borrowers assume. Five questions cover most of the ground:
- Is the penalty calculated as three months’ interest, or as the interest rate differential?
- What’s my annual prepayment privilege, and does it reset each calendar year or on the anniversary?
- Can I port this mortgage, and how many days do I have to complete both transactions?
- Does the contract allow a blend and extend if I need to borrow more?
- Is the mortgage assumable by a future buyer?
Get those answers in writing before you sign, not over the phone after you’ve made an offer on your next place.
One more number worth keeping in your head: the prepayment penalty is calculated on the balance at the time you break, not the amount you originally borrowed. Pay down the principal aggressively in the early years and the cost of leaving drops with it. The borrowers who recover fastest from a bad mortgage aren’t the ones with the best rate. They’re the ones who understood the exit clause on day one and treated their prepayment privileges like a routine, not a rainy-day option.