What does it mean to port a mortgage in Canada?

Porting a mortgage means transferring your existing mortgage — including its rate, remaining term, and balance — from your current property to a new property you are purchasing. If approved, you avoid paying the prepayment penalty you would otherwise owe for breaking the mortgage. The mortgage moves with you rather than being discharged.

Can you always port your mortgage in Canada?

No. Portability is a privilege, not a right — it depends on your mortgage contract and is subject to lender approval. You must qualify for the new mortgage under current stress test rules, the new property must meet the lender's guidelines, and the timing between your sale closing and new purchase closing must fit within the lender's portability window (typically 30–120 days).

What happens when you port a mortgage and need to borrow more?

When the new property costs more than your existing mortgage balance, lenders use a blended rate approach. The existing mortgage carries its original rate; the additional amount is issued at the current market rate. The two are blended into a single new payment at a weighted average rate, usually extended to a new term.

Do you get penalized for porting a mortgage?

In most cases, no penalty applies if the port is successful. However, if your lender requires a blend-and-extend as part of the port, you are locked into their current rates for the new top-up portion. If the port falls through (deal collapses, timing misses the window), the full prepayment penalty typically applies.

What is the portability window for mortgages in Canada?

The portability window is how many days you have between closing on your sale and closing on your purchase. Big banks typically allow 30–90 days. Some monolines and credit unions extend the window to 120 days. If your purchase closes outside this window, the port is denied and the full prepayment penalty applies.

Mortgage Portability in Canada: How It Works and the Blending Math

What Is Mortgage Portability?

When you sell your home and buy a new one, you have three options for your existing mortgage:

Option	What Happens
Port the mortgage	Transfer it to the new property — penalty avoided
Break and refinance	Pay the penalty and get a new mortgage at current rates
Vendor-take-back or assumption	Buyer takes over your mortgage (rare, lender must approve)

Portability is most valuable when your existing rate is lower than current market rates. If you locked in at 2.9% during 2021–2022 and current 5-year rates are 4.5%+, porting preserves that below-market rate.

How Portability Works: The Basic Scenario

Same Balance Port

If you sell your $600,000 home and buy a $600,000 home with the same mortgage, portability is straightforward:

Your existing mortgage ($350,000 at 2.89%) transfers to the new property
Same term, same rate, same payment
No penalty

Requirements:

Qualify under the current stress test (contract rate + 2%)
New property must meet lender’s LTV and property-type guidelines
Timing must be within the portability window

The Blending Math: When You Need More Money

Most moves involve upsizing. If your current mortgage is $350,000 but your new property requires a $500,000 mortgage, you need a top-up of $150,000.

How Blended Rates Are Calculated

The lender issues two “tranches” and blends them:

Tranche	Amount	Rate	Remaining Term
Ported amount	$350,000	2.89%	3 years
Top-up amount	$150,000	4.84% (current 5-yr)	5 years (new)
Blended mortgage	$500,000	? weighted average	New term

Blended Rate Formula

Blended Rate = (Amount₁ × Rate₁ + Amount₂ × Rate₂) ÷ Total Amount

($350,000 × 2.89%) + ($150,000 × 4.84%) = $10,115 + $7,260 = $17,375

$17,375 ÷ $500,000 = 3.475% blended rate

What Term Do You Get?

Most lenders require you to extend to a new full term on the blended mortgage. This is called “blend and extend.” Your 3 years remaining at 2.89% gets extended to a fresh 5-year term at 3.475%.

This is a mixed outcome:

Good: No penalty paid
Neutral: Rate is between your old rate and current market rate
Potential downside: You’re locked into 5 more years when rates might fall

Lender Portability Policies: Key Differences

Lender	Portability Window	Same-Lender Requirement	Notes
TD	60 days	Yes	Blend and extend required
RBC	45–90 days	Yes	Rate hold for purchase sometimes available
BMO	30–60 days	Yes	Short window is a common complaint
Scotia	90 days	Yes	Some flexibility with bridge financing
CIBC	90 days	Yes
First National	90 days	Yes	Monoline; generally favourable terms
MCAP	120 days	Yes	Longer window is advantageous

Key rule: You can only port to a property that will be financed with the same lender. If you want to switch lenders on the purchase, you must break the mortgage and pay the penalty.

The Timing Problem

The most common portability failure is a timing mismatch:

Your sale closes November 1
Your purchase closes February 1
Window is 90 days — that’s 92 days

Result: Port denied. Full prepayment penalty applies.

Solutions for Timing Gaps

| Bridge Financing | Lender provides short-term loan to bridge the gap between sale and purchase closing. Not the same as the portability window extension — you still need to close the purchase within the port window. | |Purchase Deposit Loan | If you need to firm up on a purchase before your sale closes, this is a separate facility. | | Extend Portability Window | Some lenders will extend by 30 days with a written request and a purchase agreement in hand. |

When Portability Does Not Save You Money

Portability is only valuable if your existing rate is below current market rates. Run the numbers both ways:

Scenario: Port vs. Break and Get New Mortgage

Metric	Port Scenario	Break and Refinance
Mortgage balance	$500,000 blended	$500,000 new
Rate	3.475% blended	4.44% new 5-year
Monthly payment	$2,486	$2,741
Monthly savings from porting	$255	—
5-year total interest	$99,825	$109,780
5-year savings from porting	$9,955	—

In this scenario, porting saves nearly $10,000 over 5 years — even after the blend extended your rate above your original 2.89%.

Now reverse the scenario: if your original rate was 5.5% and current 5-year rates are 4.3%:

Breaking and getting a new mortgage at 4.3% beats porting
The penalty might be worth paying

Rule: If current market rates are within 0.5% of your blended rate, break-even analysis favours breaking.

Common Portability Pitfalls

Property type change: Porting from a house to a condo or from primary residence to rental often requires re-qualification under different LTV rules
Stress test re-qualification: Even on a port, you must re-qualify. If your income has dropped, you may not pass — the port is denied
Insured to uninsured transition: If your ported mortgage is CMHC-insured but the new top-up pushes you above $1.5M in purchase price, the entire mortgage may need to be restructured
Sale falls through: If your sale collapses after you’ve purchased, you hold two properties. The port may still apply, but your debt load is doubled