Porting Mortgage Canada Guide

How to transfer your existing mortgage rate to a new home — and avoid the prepayment penalty when you move.

What Is Mortgage Porting?

Porting a mortgage means transferring your existing mortgage — including its current interest rate, remaining term, and outstanding balance — from your current home to a new property when you move. If you are mid-term on a 5-year fixed mortgage at 3.5% and rates have risen to 5%, porting allows you to keep your 3.5% rate on the equivalent balance rather than breaking the mortgage and paying a penalty.

Porting is available on most closed fixed-rate and variable-rate Canadian mortgages, though the specific rules and timelines vary significantly between lenders.

How Porting Works: The Basic Mechanics

• You sell your current home and purchase a new one simultaneously (or within your lender's porting window)
• Your existing mortgage balance is transferred to the new property at the existing rate
• If the new home costs more, you may need to borrow additional funds — typically at the current market rate (blended with your existing rate)
• If the new home costs less, you may have to pay down the difference (which could trigger a partial penalty on the reduced amount)
• You must re-qualify under the stress test for any additional borrowing

The Porting Window: A Critical Detail

Most lenders require that the sale of your old property and the purchase of your new property close within a specific window — typically 30 to 90 days. If the gap between closings is longer, you may be forced to break the mortgage and re-apply, forfeiting the rate advantage. Always confirm your lender's porting window before listing your home for sale, and structure your real estate transactions accordingly.

Lender Type	Typical Porting Window	Notes
Big Six Banks	30–90 days	Varies; confirm in writing
Monoline lenders	30–120 days	Often more flexible
Credit unions	Varies widely	Check your specific agreement

Porting with a Top-Up: Blended Rates

If your new home is more expensive than your current home, you need to borrow additional funds. Most lenders allow this through a "blend and increase" — blending your existing mortgage rate with the current market rate on the additional amount. The resulting blended rate sits between your old rate and the current rate.

Example: $400,000 remaining mortgage at 3.2% (ported). New home requires $600,000 total. Additional $200,000 borrowed at current rate of 5.0%. Blended rate = (400,000 × 3.2% + 200,000 × 5.0%) / 600,000 = approximately 3.8%. This is still better than breaking the mortgage and borrowing $600,000 entirely at 5.0%.

When Porting Does NOT Make Sense

• Current rates are lower than your existing rate — you'd rather break and get the new lower rate
• Your new home is in a different province (many lenders don't port across provincial lines — check your agreement)
• The new property doesn't meet the lender's property requirements (rural, unique construction, leasehold)
• You no longer qualify under the stress test for the new mortgage amount
• Your lender doesn't offer porting on your specific product

Porting vs. Breaking and Re-Applying

With rates having risen significantly from the 2020–2021 lows, homeowners who locked in sub-3% rates are in a uniquely valuable position — their rate is an asset. For these borrowers, porting preserves enormous value. A homeowner with $500,000 at 2.5% versus the current 5.0% saves approximately $12,500 per year in interest by porting instead of breaking. Over a remaining 3-year term, that is $37,500 — dwarfing most legal and administrative costs of the porting transaction.