If you’re selling your current home and buying a new one while locked in a fixed rate mortgage, you face a choice: pay the break penalty (potentially thousands of dollars) or port your mortgage to the new property. In 2026, with penalties at many lenders running $10,000–$25,000+, understanding mortgage portability could be one of the most valuable pieces of knowledge you carry into your next move.
What Is Mortgage Portability?
Mortgage portability means transferring your existing mortgage — including the remaining balance, rate, and term — from your current property to your new one. Instead of breaking your mortgage and incurring a penalty, you move the contract to the new home. You still need to requalify under today’s lending guidelines, but you avoid the break penalty entirely.
How Porting Works in Practice
| Scenario | What Happens | Your Rate |
|---|---|---|
| New home = same price | Port existing balance to new property — no changes | Your existing rate maintained |
| New home = higher price (blend-and-extend) | Existing balance ported at old rate; additional amount at current rate; blended rate calculated | Blended rate between old and new |
| New home = lower price | Port up to new LTV — excess balance must be repaid (may trigger partial penalty) | Existing rate on ported portion |
Blend-and-Extend: The Upsizing Scenario
Example: You have $420,000 remaining on a mortgage at 2.49% with 2 years left. Your new home needs $620,000 in financing. The lender blends your existing rate with today’s 5-year fixed rate of 4.09% across the new combined balance of $620,000 — then extends your term to 5 years.
- Existing $420K at 2.49% + New $200K at 4.09% = Blended rate ~3.02% on $620K
- Monthly payment at 3.02% on $620K (25-year): ~$2,942/mo
- Monthly payment at 4.09% on $620K (25-year): ~$3,286/mo
- Monthly saving from porting: ~$344/month = $20,640 over 5 years
The Port Window: Timing Matters
Most lenders offer a port window of 30–120 days — the gap between selling your existing property and closing on your new one. If your closings are more than 90–120 days apart, porting may not be possible and you’ll need to break and re-mortgage. Always confirm your lender’s port window before listing your current home for sale.
Porting vs. Breaking: When Breaking Wins
Porting isn’t always the best choice. If your existing rate is above today’s market rate — for example, a 5.29% fixed from 2023 — breaking and re-mortgaging at today’s ~4.09% may save more over your remaining term than the penalty costs. Always model both scenarios with your broker before deciding.
Get a port vs. break analysis from an Ontario mortgage broker at mrates.ca.