Extending Your Mortgage Amortization in Canada: How It Works and What It Costs

Extending the amortization means stretching what you still owe over more years than you have left. The lender recalculates the payment on the same balance over the longer period, so each payment is smaller and the loan takes longer to clear. It is most often asked for at renewal, when a higher rate would otherwise raise the payment, and sometimes mid-term when money is tight. This page covers an existing mortgage; choosing the amortization on a new purchase is a separate decision, covered under 25 vs 30 year amortization.

How an extension changes the payment and the interest

Take a $430,000 balance with 20 years of amortization left, renewing at 4.50% . Without an extension the payment is set to clear the balance in 20 years; each extra five years lowers it, and adds interest over the rest of the loan, assuming the rate stays the same throughout.

Two things drive the extra cost. The balance falls more slowly, so interest is charged on a larger amount for longer, and the extra years themselves carry interest. In practice the rate will change at each renewal, so the lifetime figures are a guide to scale rather than a forecast. The mortgage amortization calculator shows the year-by-year balance for any amortization.

When you can extend

At renewal with your current lender. Renewal is the usual moment, because the lender is writing a new term anyway. Whether it agrees, and how far it will stretch the amortization, is the lender’s decision; the renewal offer should show the amortization it is based on. If your lender is a bank or other federally regulated lender, its renewal statement arrives before the term ends, which is the point to ask.

Mid-term, when you’re in difficulty. A longer amortization is one of the relief measures regulators expect banks to consider. If you're at risk of mortgage default and working with your lender on a solution, a federally regulated lender such as a bank is expected to offer relief suited to your circumstances: for example a payment deferral (usually up to 4 months), waived prepayment penalties on a lump-sum payment that avoids negative amortization or when you sell your home, waived internal fees and no interest on interest for a limited period, or a longer amortization with a plan to restore it. Relief can raise what the mortgage costs in total. Mortgage payment deferral is the other common option, and the missed mortgage payment guide covers what happens if a payment slips before anything is agreed.

When switching lenders at renewal. Since November 21, 2024, OSFI no longer requires the minimum qualifying rate for a straight switch of an uninsured mortgage, which keeps the same amortization and balance (plus up to $3,000 for switching costs). Extending the amortization as part of the move takes it outside that exemption, so the new lender qualifies you again; switching mortgage lenders covers the rules for insured and uninsured loans.

By refinancing. A refinance replaces the mortgage with a new one, so the amortization can be reset, usually along with borrowing more. It means a new application and, mid-term, a prepayment penalty; how to refinance a mortgage walks through it and renewal vs refinance compares the two.

New purchases follow different rules

The amortization limits for insured mortgages on a home purchase are set by federal rules. Since December 15, 2024, insured 30-year amortizations have been open to all first-time buyers and all buyers of new builds; the 30-year amortization rules set out who qualifies.

The trade-off

An extension trades a lower payment now for more interest and slower equity later. It tends to help when:

• the payment at renewal would otherwise crowd out essentials, and the alternative is falling behind;
• income has dropped for a period you expect to end, such as a parental leave or a job search;
• the money freed up pays down debt at a higher rate than the mortgage.

It costs more for less benefit when the higher payment is affordable, when the mortgage is close to paid off (the extra years add interest on a balance that was about to disappear), or when the amortization has already been extended before.

Getting back to the original schedule

An extension doesn’t have to be permanent. Paying more than the new minimum, up to the limit your contract allows, brings the payoff date back. With the 25-year extension above , keeping up the 20-year payment of $2,711 instead of $2,380 clears the loan on the original 20-year schedule, as long as the rate doesn’t change. How much extra you can pay without a penalty depends on your prepayment privileges; the mortgage calculator with extra payments shows the effect of any amount. A lump-sum prepayment normally shortens the loan in the same way, while a mortgage recast takes the benefit of one as a lower payment instead. Switching to accelerated bi-weekly payments also pays the loan down faster, as explained in the payment frequency guide.

Asking for an extension

1. Work out the payment at the offered rate on your remaining amortization, and at the longer one you want; the mortgage renewal calculator does both.
2. Ask the lender the longest amortization it will offer on your mortgage, and whether any fee applies.
3. Check that the written renewal offer or amending agreement states the new amortization and payment.
4. Note the total interest at each amortization, so the extra cost is a known number.

For how much the payment rises at renewal in the first place, see payment shock at renewal. The mortgage payments hub lists the other guides on managing payments.