What actually happens when your mortgage renews?

Somewhere between five and one hundred and twenty days before your mortgage matures, a letter or an email arrives with a new rate and a form to sign. It looks routine, and lenders design it to feel routine — most Canadians renew with the same institution that had them at the previous rate, often the same one their parents used. But a renewal is a new loan. The old contract ends, a new one begins, and every term of it — the rate, the term length, sometimes the amortization — is open for a conversation that most people never have.

This matters more now than it did for the mortgages that renewed through the low-rate years, because the gap between the rate you locked in and the rate you renew into can be large enough to change your monthly payment by hundreds of dollars. Knowing what is actually being reset, what the number in the letter really means, and which parts of it are negotiable is the difference between a renewal that costs you and one that works in your favour.

Why a Canadian mortgage renews at all

A Canadian mortgage is built from two numbers that most borrowers mentally collapse into one: the term, the length of the contract you sign with a specific rate and lender, and the amortization, the total time it will take to pay the loan to zero at that payment. A five-year term against a twenty-five-year amortization is normal, and the two are not the same thing — the term is a slice of the amortization, not the whole of it.

This split exists because no lender wants to guarantee a rate for twenty-five years, and few borrowers would want the rate that guarantee would cost. So the loan is chopped into terms — commonly one, three, or five years, sometimes longer — and at the end of each one, the remaining balance and remaining amortization roll into a new term at whatever rate is available then. A renewal is simply that rollover. Nothing about your balance or your progress toward zero is lost; only the rate is up for renegotiation, on a schedule set at the start.

Contrast this with a refinance, which is a different transaction entirely: breaking the current contract before maturity, usually to borrow additional money, change lenders mid-term, or restructure debt, and it typically comes with a prepayment penalty for ending the term early. Renewal happens at the natural end of the term and carries no penalty for moving your business elsewhere — a distinction that matters later in this guide, because it is exactly the freedom people forget they have.

The arithmetic behind renewal shock

The payment change at renewal is not proportional to the rate change — it compounds with how much amortization is left, which is why two borrowers who started at the same rate can face very different shocks. Take a mortgage that had $400,000 remaining with 25 years left on the amortization, renewing off a 4.00% rate. Here is what the same balance costs per month at a range of renewal rates, using the semi-annual compounding Canadian fixed mortgages actually use:

A rate increase that sounds modest on paper — 4.00% to 5.50%, a move of a percentage and a half — adds nearly $340 to the monthly payment on this balance, over $4,000 a year, out of after-tax income that did not also go up. That gap is what "renewal shock" means in practice, and it is the reason renewal deserves the same seriousness as the original purchase: the amount at stake is not a one-time closing cost, it is a permanent change to a monthly obligation that runs for years. Run your own balance and remaining amortization through the mortgage renewal calculator rather than eyeballing it against the table above — amortization length and balance both move the shock by more than the headline rate difference suggests.

The number in the letter is an opening offer

The rate quoted in a renewal letter is close to the lender's posted rate, and posted rates carry a built-in margin most borrowers never see, because the lender is quoting to the segment of customers who will not negotiate — which is most of them. Renewal letters are mailed to everyone, discounted and undiscounted borrowers alike, and the lender has no incentive to lead with their best number when inertia is doing most of the work for them.

The leverage a renewing borrower has is real: a lender pays acquisition costs to win a new customer, and keeping an existing one is cheaper even at a lower rate than the letter first quotes. Calling the lender's retention line — not the general branch line — and stating plainly that you are comparing offers elsewhere routinely produces a better number than the one on the page, sometimes meaningfully better. It costs a phone call and a few days of patience, against a rate gap that compounds for years.

The other lever is timing. Most lenders will hold a quoted rate for a window — commonly around four months — before your maturity date, and if rates fall in that window some will also let you take the lower one. That combination means starting the comparison process early costs nothing and only helps: there is no version of "I locked in too soon" if the lock comes with a rate-drop option, only a version of "I waited too long to start comparing."

Switching lenders: when the stress test actually applies

The federally mandated stress test — qualifying at the greater of your contract rate plus a fixed spread or a set floor — is the thing that makes people assume switching lenders at renewal is complicated. It applies to a new mortgage application, and a lender you have never borrowed from treats your renewal as exactly that: a new application, with new underwriting, run at the stress-tested rate rather than the rate you will actually pay.

Staying with your current lender at the actual renewal date is the one case where the stress test does not apply — the rule exists to protect against new debt being taken on beyond a borrower's means, and a renewal with no change in loan amount and no change in lender is not new debt in that sense. This is a real advantage of staying put, and it matters most for anyone whose income, debt load, or credit profile has moved in a direction that would make a fresh qualification harder than it was originally — a job change, a new car loan, a lower credit score. For everyone else, the stress test is a qualification hurdle, not a cost: if your income and debts still comfortably clear it, switching lenders costs at most a discharge fee, some paperwork, and the appraisal a new lender may request, none of which resembles the penalty attached to breaking a mortgage mid-term. How much house you can carry is worth revisiting with current income and debts before assuming a switch is straightforward — the qualifying math has likely moved since the original purchase, in one direction or the other.

Choosing the next term

The term decision at renewal is really a bet on the direction of rates balanced against how much payment-change risk you can absorb. A shorter term — one or two years — costs a bit more in rate today in a normal-shaped market but gets you back to the negotiating table sooner if rates are expected to fall, or if you expect to sell or refinance before a longer term would end anyway. A longer term — five years or more — locks in certainty: the payment you sign up for is the payment you have regardless of what happens to rates in between, at the cost of missing a rate drop if one arrives.

There is no universally correct answer, but there is a wrong way to choose: picking the term with the lowest headline rate without asking what happens at the next renewal if the bet is wrong. A borrower who takes a short term expecting rates to fall and is wrong twice in a row has taken on more renewal-shock risk, not less, by trying to time it. If your income has little slack for a payment increase, the longer term's certainty is worth its modest rate premium; if your income can absorb a swing and you have a genuine reason to expect lower rates ahead, the shorter term is a reasonable trade to make with eyes open.

Renewal is also a chance to restructure

Because a renewal creates a brand-new contract, it is also the cleanest moment to change things about the mortgage that have nothing to do with the rate — moments that don't exist mid-term without a penalty attached.

Extending the amortization back out is the direct answer to a payment shock that a household genuinely cannot absorb: taking the same $400,000 balance from a 25-year to a 30-year amortization at 6.50% drops the payment from $2,679 to roughly $2,506 a month — about $174 of relief, at the real cost of five more years of payments and materially more interest paid over the life of the loan. It is a lever worth knowing about, not a lever worth pulling by default; it trades a short-term problem for a long-term one and should be a deliberate choice, not the path of least resistance.

The opposite move works too. Anyone who has built up cash — a bonus, an inheritance, simple discipline — can apply a lump sum at renewal with no prepayment penalty, because the old contract is ending anyway rather than being broken early. Paying $20,000 against that same $400,000 balance before renewing at 6.50% drops the new payment from $2,679 to about $2,545 a month, a saving of roughly $134 every month for the life of the new term, from a single one-time payment. The extra payment calculator shows what a lump sum or an increased regular payment does to both the payment and the payoff date, and if the debt-versus-invest question is live for that cash, extra payments against investing it walks through how to compare the two properly rather than by feel. Homeowners specifically weighing whether to accelerate the mortgage using tax-advantaged, invested leverage should also read the Smith Manoeuvre before committing new cash to the mortgage rather than into that structure — it is not for everyone, but the renewal moment is exactly when it is worth considering, before the next five years of payments are locked in.

None of this requires acting the day the letter arrives. Model your actual balance and remaining amortization on the mortgage calculator against a few plausible renewal rates, get a competing quote, and only then decide whether the letter in front of you is worth signing as written.