Moving to a new home? Compare the cost of porting your existing mortgage (blended rate, no penalty) versus breaking it and renewing at today's lower market rate. See which option saves you more money over 5 years.
Portability allows you to transfer your existing mortgage — including your current interest rate and remaining term — to a new property when you sell your home and buy another. Most Canadian lenders allow porting, typically with a 30–120 day window between closing your sale and completing your purchase. Porting avoids the break penalty and locks in your current rate on the ported portion.
When you port your mortgage and need additional funds for a more expensive property, the lender blends two rates together: your existing rate (on the ported balance) and the current market rate (on the top-up). The resulting blended rate is a weighted average of both rates by dollar amount. The blended rate is typically higher than today's market rate but lower than your original contract rate.
Breaking and renewing makes sense when today's market rate is significantly lower than your existing rate and the penalty cost is relatively small. If the 5-year interest savings from the lower market rate outweigh the upfront penalty, breaking delivers better long-term value — even after paying the penalty. This calculator shows the full 5-year cost of each option so you can compare directly.
Most lenders offer portability, but the exact conditions vary. Big banks generally allow ports within 60–120 days and may use a "blend-and-extend" product. Monoline lenders may have stricter windows (often 30–60 days). Some lenders require you to qualify at the stress test rate on the full new mortgage amount — even on a port. Always confirm portability terms with your current lender before listing your home.