Mortgage Portability When Moving
Check the permitted window between the sale and purchase, then the balance and rate eligible for transfer.
Published 2026-07-21
Moving mid-mortgage immediately evokes the penalty; the portability clause, present in most contracts and rarely read, often offers a far cheaper exit. The principle: carrying the existing balance and rate to the new property. The conditions: a window between the sale and the purchase, often 30 to 120 days; full requalification — income and new property, appraisal included — porting exempting no one from anything; and, if the new house costs more, additional financing at the current rate, merged into a blended rate whose formula gets requested in writing. The risk to cover: a failure of the criteria mid-stream brings back the entire penalty, hence the importance of confirming every condition before the transactions go firm. This article details the typical conditions, the blended-rate calculation and the comparison with a clean break — to be made with numbers in hand before choosing.
Read the clause before making an offer
Portability is a clause in the mortgage contract, not a universal right: some loans provide it broadly, others frame it narrowly, a few exclude it. Reading it precedes listing the home and making an offer, because it changes the move's entire calculation: a portable loan at a good rate is worth thousands compared with breaking and paying a penalty. The elements to note: does portability exist, what time window does it grant between the sale and the new purchase, what qualification conditions apply, and how is additional financing handled. Those answers, obtained from the lender in writing before the transactions, steer the whole strategy: they say whether your rate travels with you or stays behind. Read them before you shop.
Respect the window between the two transactions
Portability imposes a maximum delay between selling the old property and buying the new one, often thirty to a hundred and twenty days depending on the contract, sometimes with different mechanics according to the transactions' order. That delay becomes a real planning constraint: a quick sale followed by a long search can let the window expire and turn the port into a penalized break. Coordination therefore happens with the window in mind, closing dates negotiated accordingly, and the lender informed of the planned calendar. When the timing tightens, bridge financing can fill the gap between the two closings — a solution to price in advance rather than discover in a panic during moving week.
Handle the new purchase's additional financing
Portability carries the existing balance at its rate; it does not finance the price difference. A more expensive new property requires additional financing, granted at the current rate, and the two portions merge into a blended rate weighted by each one's size. The exact formula is requested from the lender, figures in hand: what blended rate results from porting this balance at this rate plus this new amount at the offered rate? That figure is then compared with a fully new mortgage's rate at a competitor, the break penalty subtracted. Portability wins comfortably when the old rate sits well below the market and the ported balance dominates; the advantage thins when the new financing far exceeds the old balance.
Plan for the criteria failing
Portability exempts you from nothing: the lender requalifies the income, appraises the new property, applies its usual criteria — and a refusal at that stage brings back the break-with-full-penalty scenario. That risk is managed upstream: confirm every criterion in writing before making the transactions firm, obtain the lender's conditional commitment, and keep the potential penalty priced in a plan B. Atypical properties — cottages, income buildings, land — deserve particular attention, some lenders refusing to port toward assets they would not have financed in the first place. The complete plan fits on one page: criteria confirmed, dates coordinated, blended rate calculated, plan B priced — and the decision is made with all three scenarios in hand. Nothing is left to the day itself.
Quebec scenario: compare before confirming
Transferred from Saguenay to Quebec City in the third year of a 4.2% term, a couple dreads the $7,800 penalty that breaking would represent, with current rates above 5.5%. Their contract, however, contains a portability clause, and everything lives in its conditions. The window first: the lender grants 90 days between the sale and the new purchase to carry the mortgage over; their two transactions, six weeks apart, fit the frame. The scope next: the $286,000 balance and the rate travel as they are, but the new house costs more, and the additional $60,000 is financed at today's rate, merged into a blended rate between 4.2% and 5.6%. Qualification remains: porting a mortgage does not exempt anyone from requalifying income and property, and an appraisal of the new house is required. The couple gets every condition in writing before lifting their purchase conditions, because a failure of the portability criteria mid-stream would bring back the full penalty. The final math produces a blended 4.5%: the clause, never read before the transfer notice arrived, turns out to be worth about $6,300 against a clean break.
Checklist
- Read the contract's portability clause
- Verify the window between sale and purchase
- Plan for the full requalification
- Have the blended rate priced in writing
- Compare with breaking and its penalty
- Confirm every criterion before the transactions go firm
- Keep the potential penalty as a costed plan B
- Coordinate both transactions' dates
- Archive the lender's confirmations
Frequently asked questions
What conditions frame porting my mortgage?
A window between the sale and the new purchase, often 30 to 120 days per the contract; full requalification of your income and the new property, appraisal included; and the transfer of the existing balance and rate as they are. Each condition gets confirmed in writing before purchase conditions are lifted.
How is the gap financed if the new house costs more?
Through additional financing at the current rate, merged with the ported balance into a rate blended between old and new. Ask the lender for the blended-rate calculation, figures in hand, and compare it with breaking and paying the penalty at a competitor.
What happens if portability fails along the way?
The full break penalty becomes payable again: an exceeded window, a refused requalification or an ineligible property brings back the ordinary scenario. Hence the importance of confirming every criterion before the transactions go firm — and of keeping the potential penalty in a costed plan B.