Porting a Mortgage in Canada: What You Actually Keep When You Move
Stacking $400,000 of new money onto a ported 2.89% mortgage waters the blended rate down to 3.890% — and the monthly saving still goes up, not down.
Saturday, 17 October 2026. Porting a mortgage moves your existing contract to your next property instead of breaking it and paying a penalty. With the Bank of Canada holding at 2.25%, prime at 4.45%, the best insured five-year fixed at 4.34% and the lowest uninsured fixed at 5.09%, the live question for anyone moving this autumn is what a ported rate is worth once the lender blends new money into it. On a $480,000 balance at 2.89%, the answer is about $546 a month — and it only rises to $552 after you stack $140,000 of fresh borrowing on top at 5.09%. The blended rate gets diluted. The dollars do not.
That distinction decides most move-up decisions, and almost nobody runs it. Borrowers see 3.387% on the commitment where they used to have 2.89% and conclude the port has been watered down. It has not. Porting a mortgage protects a fixed quantity of cheap money, not a percentage.
What porting a mortgage actually moves
A port carries four things to the new property: your rate, your remaining term, your remaining amortization, and your lender. It does not carry your approval — the file is underwritten again as if it were new.
The alternative is to discharge the mortgage, pay a prepayment penalty, and originate a fresh one. On a fixed mortgage that penalty is the greater of three months' interest or the interest rate differential, and the IRD calculation at a large bank can run to several times the three-month floor. We cover that arithmetic in our guide to the mortgage prepayment penalty in Canada.
Here is what you would be signing instead if you broke the contract today, on a $500,000 mortgage over 25 years:
| Rate available 17 October 2026 | Rate | Payment on $500,000 / 25 yr |
|---|---|---|
| Best five-year variable, insured (Ratehub) | 3.43% (prime − 1.02%) | $2,477.91 |
| Best five-year fixed, insured (Ratehub) | 4.34% | $2,723.07 |
| Second-best insured five-year fixed (nesto, 16 Oct) | 4.59% | $2,792.44 |
| Lowest uninsured fixed (nesto, 16 Oct) | 5.09% | $2,933.69 |
| Big Six average five-year fixed (nesto, 16 Oct) | 5.18% | $2,959.47 |
A mover with more than 20% equity in the new home is an uninsured borrower, so 5.09% is the honest comparison rate for most move-ups — not the 4.34% headline, which is insured pricing. Payments use Canadian semi-annual compounding.
What porting a mortgage does to your rate when you borrow more
Porting and borrowing more at the same time is a port-and-increase. The lender prices the new money at today's rate and blends it with your existing rate, weighted by dollars. Take a $480,000 balance at 2.89% and add new money at 5.09%:
| New money added | New mortgage | Blended rate | Payment (20 yr) | Monthly saving vs all-new at 5.09% | Share of the 220 bp gap kept |
|---|---|---|---|---|---|
| $0 (straight port) | $480,000 | 2.890% | $2,631.60 | $545.97 | 100.0% |
| $50,000 | $530,000 | 3.098% | $2,960.04 | $548.53 | 90.6% |
| $100,000 | $580,000 | 3.269% | $3,288.93 | $550.63 | 82.8% |
| $140,000 | $620,000 | 3.387% | $3,552.30 | $552.06 | 77.4% |
| $250,000 | $730,000 | 3.643% | $4,277.38 | $555.17 | 65.8% |
| $400,000 | $880,000 | 3.890% | $5,267.40 | $558.14 | 54.5% |
Read the last two columns against each other. By the time you have added $400,000 of new money, the blend has surrendered 45.5% of the rate advantage — 2.89% has become 3.890%. Yet the monthly saving has gone up, from $545.97 to $558.14. The spread between the best and worst row in that column is $12.17 a month.
The reason is mechanical. The discount only ever applied to $480,000 of principal. Borrowing more does not shrink it; it parks a larger block of market-rate money beside it and drags the average. So value a port in dollars per month against the all-new alternative, never as a change in the headline rate. A borrower who walks away from porting a mortgage because "the blended rate is almost 3.9% anyway" is giving up roughly $558 a month.
A worked move-up: $480,000 at 2.89% plus $140,000
Take the middle case. You hold $480,000 at 2.89% on a five-year fixed signed in February 2022, maturing February 2027, with 20 years of amortization left. You are moving to a home that needs a $620,000 mortgage, so $140,000 of new money comes in at 5.09%.
- Blended rate: 3.387% — ($480,000 × 2.89% + $140,000 × 5.09%) ÷ $620,000.
- Payment: $3,552.30 against $4,104.36 if the whole $620,000 were written at 5.09%.
- Monthly saving: $552.06. Over five years, $33,123.71.
- Interest over the first 60 months: $94,747 blended versus $144,021 at market — $49,274 less.
- Principal retired over those 60 months is $16,151 higher, because more of a lower-rate payment is principal.
One caveat on term. Some lenders blend to your existing maturity, leaving you 16 months and then a normal renewal; others reset the clock to a fresh five-year term at the blended rate. The second version is a materially different trade — the same bet we examined in blend and extend in Canada. Ask which one you are being offered, because the figures above assume the rate holds for five years.
Porting a mortgage also protects your qualifying rate
This is the part that gets missed, and it often decides whether the move happens at all. The minimum qualifying rate is the greater of your contract rate plus two percentage points or 5.25%. A ported blend of 3.387% qualifies at 5.387%. Today's 5.09% qualifies at 7.09%.
On $620,000 over 20 years, that is a stress-tested payment of $4,204.73 instead of $4,802.20 — $597.47 a month less debt service for the same house. Over 25 years the gap is $633.34. If your ratios are tight, porting a mortgage is not a way to save money on a house you already qualify for; it is the reason you qualify.
A straight port with no increase can also qualify at the 5.25% floor rather than contract-plus-two, because 2.89% plus two is only 4.89%. Asking for more money moves you off that floor — the same mechanic that catches renewers who ask for a longer schedule, as we set out in amortization extension at renewal.
When your rate is above market, the penalty floor still favours the port
Suppose the opposite: you signed in 2023 and hold $510,000 at 5.49% with 20 months to run and 22 years of amortization. Today's uninsured 5.09% looks better, so breaking seems obvious. Run it.
The payment falls from $3,313.51 to $3,199.55 — a saving of $113.96 a month, or $2,279.18 across the 20 remaining months. On an interest basis you save $3,304. Three months' interest on $510,000 at 5.49% is $6,999.75, and that is the floor; the IRD could be higher. You are down roughly $3,696 before any legal or appraisal cost.
The breakeven is about 42 months of remaining term on an interest basis. A 40-basis-point improvement cannot repay even the three-month penalty floor until you have three and a half years left to run. With 20 months left, porting a mortgage at a rate 40 bps above market is still the right answer, and the gap has to be far wider, or the term far longer, before breaking wins.
Where porting a mortgage falls apart
Four failure modes, in the order they actually bite:
- The window. Lenders allow roughly 30 to 120 days between the sale closing and the purchase closing, and the number is specific to your commitment — confirm it rather than assuming 90. Miss it and the port lapses into a break, penalty included. If the dates do not line up, bridge financing is the usual fix.
- Requalification. Porting a mortgage is underwritten as a new loan: income, credit and debt-service ratios are all rechecked, and the new property is appraised. Self-employed income that passed in 2022 gets looked at again on 2026 standards.
- The product. HELOCs are not portable. No-frills and restricted mortgages often are not. Closed variable-rate mortgages are frequently excluded, or must convert to fixed first. Insured mortgages port, but the insurer has to re-approve the property.
- The lender. A port keeps you with your current lender by definition. If their offer on the new money is poor, you are choosing between a weak rate on the increase and a penalty on the whole balance.
How to decide on porting a mortgage
- Pull your current balance, rate, maturity date and remaining amortization off your last statement. All four matter.
- Ask your lender for the port window in days, the administration fee, and whether a port-and-increase blends to term or resets to five years. Get it in writing.
- Work out the new money: purchase price, less your down payment from sale proceeds, less the ported balance.
- Calculate the blend yourself: (old balance × old rate + new money × quoted new rate) ÷ total. If the commitment shows a higher rate than your arithmetic, ask why.
- Price the payment at the blend and at today's uninsured rate over the same amortization. The difference in dollars per month is what the port is worth — not the change in the rate.
- Get the penalty quote in writing before you compare. Three months' interest is the floor, not the number.
- Divide the penalty by the monthly saving from breaking. If the result is more months than you have left in your term, port.
- Check the qualifying rate on both paths. If the ported blend is what clears your ratios, the port is not optional.
Value porting a mortgage in dollars per month, not in basis points. In the worked case above, going from zero to $400,000 of new money cost the headline rate a full percentage point and cost the monthly saving nothing. And if your contract rate sits above today's market, check the remaining term before you reach for the penalty: under roughly three and a half years, porting a mortgage almost always still wins.
Common questions
Can I port a mortgage to a cheaper home?
Yes — this is a port-and-decrease. The shortfall is treated as a prepayment, so your annual prepayment privilege may absorb part of it penalty-free, and the excess attracts a partial penalty on that portion only. It is usually far cheaper than discharging the whole balance, but get the figure quoted before you firm up the sale.
Does porting a mortgage cost anything?
Expect a lender administration fee in the low hundreds, an appraisal on the new property, and the standard legal cost of the purchase you were paying anyway. Those sit an order of magnitude below a fixed-rate penalty: three months' interest alone on a $480,000 balance at 2.89% is $3,468.
Does porting a mortgage let me change lenders for a better rate?
No. A port is a change of security with the same lender. Moving lenders means discharging the mortgage and paying the penalty, which is the comparison in step seven above. RateShop can price your increase against the whole market, but if the gap does not beat the penalty, staying put is the answer.
Rates and market expectations here are dated and will move. The Bank of Canada's next decision is 28 October 2026, with the Monetary Policy Report; September CPI lands Monday 19 October at 08:30 ET. Nothing here is a rate guarantee or an approval.
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