How to break your Canadian mortgage — and what it actually costs

Why breaking costs money

A closed mortgage is a contract: the lender lent you money at a specific rate for a specific period, and in exchange you committed to pay them interest at that rate for the whole term. Breaking early means the lender loses the interest they were counting on.

The prepayment penalty exists to compensate the lender for that lost interest. It's not arbitrary — it's a contractual recovery of expected revenue. But the method used to calculate it varies wildly between lenders, and that's where most borrowers get surprised.

Variable-rate mortgages: 3 months interest

If you have a closed variable-rate mortgage, your prepayment penalty is calculated as 3 months of interest at your current rate:

Penalty = current balance × current rate ÷ 4

Worked example

• Balance: $500,000
• Rate: 5.00%
• Penalty: $500,000 × 5.00% × (3/12) = $6,250

That's it. No surprises, no posted-rate trickery. This is one of the underappreciated advantages of variable-rate mortgages: predictable, modest break penalties.

Fixed-rate mortgages: the IRD trap

Fixed-rate mortgages use the greater of two calculations:

1. 3 months interest (the same formula as variable above), OR
2. Interest Rate Differential (IRD)

Whichever number is higher is what you owe. For fixed mortgages, IRD almost always wins — sometimes by a factor of 3-5x.

What IRD actually represents

IRD captures the rate spread between your contracted rate and a current comparison rate, applied across your remaining term:

Penalty ≈ (contract rate − current comparison rate) × balance × remaining months ÷ 12

The "current comparison rate" is where lenders diverge. There are two main methods.

Method A — Posted rate IRD (the big-bank approach)

This is the method that produces the highest penalties. The lender uses:

• Your contract rate — typically the discounted rate you actually got (e.g. 4.84%)
• Today's posted rate for a term matching the time left on your mortgage (e.g. 3-year posted at 6.50%)

The lender then computes the spread, applies it to your balance, and multiplies by remaining months. Big banks (RBC, TD, Scotia, BMO, CIBC) historically used this method.

Worked example

• Balance: $500,000
• Contract rate: 4.84% (you got a discount off posted at signing)
• Original posted rate at signing: 6.99%
• Today's 3-year posted rate: 6.50%
• Discount you received: 6.99% − 4.84% = 2.15%
• IRD "comparison rate": 6.50% − 2.15% = 4.35%
• Spread: 4.84% − 4.35% = 0.49%
• Wait — this is positive in your favour. IRD here would be near zero, capped at 3 months interest.

When does this method bite? In falling-rate environments where today's posted rate is much lower than at signing. Big banks compute the same way and the spread balloons.

Method B — Discounted rate IRD (monoline + broker channel)

Monoline lenders like MCAP, First National, Merix typically use:

• Your contract rate (what you actually got)
• Today's discounted rate for the equivalent remaining term (not posted)

This produces a much smaller spread because today's discounted rate is close to your contract rate.

Worked example, same scenario

• Contract rate: 4.84%
• Today's 3-year discounted rate: 4.49%
• Spread: 4.84% − 4.49% = 0.35%
• Remaining term: 36 months
• IRD: $500,000 × 0.35% × 36/12 = $5,250

Compare to 3-month interest: $500,000 × 4.84% × 3/12 = $6,050.

Penalty is the greater: $6,050 (3 months interest, here).

The same theoretical scenario produces wildly different penalties at different lenders. The method matters more than the rate spread. Read your specific contract before committing to a break.

Other IRD calculations to watch for

Some specialty lenders use:

• Present-value IRD: discount the remaining payment stream to present value at current rates. Common in commercial lending; rare in residential.
• Yield maintenance: the lender essentially makes you "make them whole" for the full lost interest. Common in commercial; can be punishing.
• Standard yield IRD: uses the Bank of Canada benchmark instead of the lender's posted rate.

If you have a non-standard mortgage (private, B-tier, commercial), your contract may use a method that's neither A nor B — read it carefully.

When you might want to break anyway

Despite the penalty, breaking can make sense:

Refinancing to a much lower rate

If you can drop 100+ basis points AND have 2+ years remaining, the interest savings often cover the penalty within 12-24 months.

Refinancing to consolidate high-interest debt

Rolling $30,000 of credit card debt at 22% into a 5% mortgage saves you about $5,000/year. Even a $10,000 IRD penalty pays for itself in 2 years.

Selling early

If you're selling and not buying again, you have no choice. The penalty comes off your net proceeds at closing.

Selling and buying again

Port your mortgage instead (see below).

Marriage, divorce, employment relocation

Sometimes life forces the break. Some lenders waive partial penalty in hardship cases — always ask.

How to minimize the penalty

1. Port instead of break

Most A-tier mortgages are portable — you can transfer the existing rate and term to a new property without breaking. If you need more mortgage on the new place, the lender blends the new amount with the existing balance at a weighted-average rate.

Porting saves the penalty entirely if you can sell and buy within the lender's port window (typically 30-120 days).

2. Use prepayment privileges first

Most A-tier closed mortgages allow you to prepay 15-20% of the original principal per year without penalty. Make that lump-sum payment before you formally break — the smaller balance produces a smaller penalty.

On a $500,000 mortgage with a $75,000 prepayment privilege:

• Use the privilege first, knocking balance to $425,000
• Then break; penalty is calculated on the smaller balance
• Total savings: roughly 15% off the penalty figure

3. Time the break to end-of-term

A mortgage at the end of its term has no remaining months to apply IRD across. Penalty drops to $0.

If you're considering breaking 12 months before maturity, you may save tens of thousands by simply waiting and renewing elsewhere instead.

4. Refinance with the same lender

Some lenders waive part or all of the IRD if you refinance to another product with them. Always ask before going elsewhere — even a 50% waiver materially changes the math.

5. Negotiate

Penalty calculations are formula-driven, but lenders have discretion in edge cases — especially long-time customers in hardship. Ask explicitly: "Will you reduce or waive the IRD?"

How to get an accurate quote

You must request a written payoff quote from your lender. Important: the verbal number a frontline rep gives you can be different from the contractual calculation. Always get it in writing.

What to ask for

• Total payoff amount (balance + accrued interest to break date + penalty + administrative fees)
• Method used (3 months interest vs IRD method A vs IRD method B)
• Comparison rate used in the IRD calc (if applicable)
• Date the quote is valid until (typically 30 days)
• Per-day adjustment if you delay the break

Red flag

If the rep can't explain the calculation method or pushes back when you ask, escalate. Some big banks have a habit of using the worst-case method by default and only switching to a friendlier method when challenged.

Common questions

Can I break a mortgage during the rate-hold / pre-approval phase?

There's no "break" before closing — you can simply not close. You'd lose your deposit on the home purchase contract, but no mortgage penalty.

What if my mortgage is open?

An open mortgage has no break penalty. You can pay it off any time. The trade-off is open mortgages carry 100-200 bps higher rates than closed.

Can I break a HELOC?

HELOCs are typically open-ended — you can close them without penalty. Some lenders charge a $200-$300 discharge fee.

Will my credit score drop if I break my mortgage?

No. Paying off a mortgage early is recorded as a closed account in good standing. Your score may temporarily dip 10-20 points if you immediately open a new mortgage, but recovers within 6 months.

What if my mortgage is "blended and extended"?

Some lenders offer a "blend and extend" that lets you blend a new rate into the existing mortgage without formally breaking. No penalty, but you typically get a worse rate than refinancing fresh. Compare both options.

Can I add the penalty to the new mortgage?

Yes — most refinances let you finance the penalty into the new balance. You'll amortize the cost over the new term rather than paying it cash at closing.

Bottom line

Before you break:

1. Get a written payoff quote
2. Determine which IRD method your lender uses
3. Run the mortgage payment calculator to project your savings at the new rate
4. Calculate breakeven: penalty ÷ monthly savings = months until you're ahead
5. Consider porting first if you're moving, not just refinancing
6. Use prepayment privileges before breaking to shrink the balance

Related reading: When to refinance, IRD penalty calculation, Mortgage portability, Renewal 90 days out.