Extend your amortization when you refinance? See the true cost first

Short answer: You can often extend your amortization when you refinance, resetting the clock to 25 or 30 years to lower your payment. The catch is interest: FCAC warns that extending your amortization means higher interest costs that "may add up to thousands or tens of thousands of dollars" ^[1]. It's a good tool for breathing room, especially if you plan to pay more again later, and an expensive one if the lower payment becomes permanent.

This guide shows how it works, the true cost on a worked example, and ways to get the relief for less. If you're thinking about a refinance, our mortgage refinancing page explains how we compare options across lenders.

How extending your amortization works

Your amortization is the total time it would take to pay off the mortgage at the current rate; your term is the length of your current contract ^[1]. Over the years the remaining amortization shrinks, say from 25 years to 19. When you refinance, the lender writes a new mortgage and you can choose a new amortization, often longer than what's left.

• With 20% or more equity, your lender sets the maximum amortization ^[1]. In our experience, 30 years is common for an uninsured refinance, and some lenders allow longer.
• A refinance must pass the stress test at federally regulated lenders: the higher of 5.25% or your rate plus 2% ^{[2] [3]}. A longer amortization lowers the qualifying payment too, which can help.
• Insured mortgages have tighter limits: 25 years, or 30 for first-time buyers and new builds ^[1], and extending an insured mortgage can mean a new insurance premium ^[4].

The true cost: a worked example

Illustration: you owe $420,000 with 19 years left and refinance at an assumed 4.49%, keeping the same rate for the whole period to show the effect of amortization alone. The rate is an assumption, not a quote.

Calculated in Python with semi-annual compounding; rate held constant; excludes refinance costs.

What it shows: stretching to 30 years frees up about $617 a month, but if the lower payment stays forever, each $1 of monthly relief costs about $225 in extra interest. After five years you'd also owe about $41,400 more than if you'd kept the 19-year schedule, which matters at your next renewal or if you sell.

Need lower payments without guessing the cost? A licensed 8Twelve agent can show your payment and total interest at different amortizations, comparing 65+ lenders at no cost to you, OAC. Start your refinance review

Get the breathing room for less

The extra interest isn't locked in. The cost depends on how long you actually use the lower payment.

Illustrative; Python, semi-annual compounding. Paying more than your scheduled payment depends on your prepayment privileges.

Many closed mortgages let you raise your payment or make lump-sum payments up to a limit without a penalty. Our guide to mortgage prepayment privileges explains how to use them. Ask for a mortgage with room to increase payments before you sign.

How a longer amortization affects qualifying

A refinance at a federally regulated lender has to pass the stress test, and the lender checks your debt service ratios at the qualifying rate ^{[2] [3]}. FCAC's guideline is total debt costs of no more than 44% of gross income ^[2]. Because a longer amortization lowers the qualifying payment, it can be the difference between a yes and a no.

Same $420,000 example; qualifying rate 4.49% + 2%. Income needed assumes $450 a month property tax, $100 heating and $600 of other debt payments, at a 44% TDS ratio. Python, semi-annual compounding. Lenders' own limits vary.

Our guide to GDS and TDS ratios explains how lenders calculate them.

Extend at refinance, at renewal or with a blend-and-extend?

Availability varies by lender; amortization changes aren't offered on every product.

When extending your amortization makes sense

• A temporary squeeze: a new baby, a job change, a renewal at a higher rate or a stretch of lower income, where you expect to pay more again later.
• Consolidating high-interest debt, where the new mortgage payment is far below what you were paying on cards and loans. Our debt consolidation savings examples show the math.
• Freeing cash flow for something with a higher return, such as paying off a 20% card, as long as you don't run the balance back up.

When it may cost more than it's worth

• If you're already refinancing for the rate. Check the penalty and break-even first; our refinance break-even guide covers that.
• If you're mid-term with a big penalty. You may get similar relief at renewal without the penalty, or with a blend-and-extend; see blend-and-extend vs refinance.
• If you're near retirement. A 30-year amortization at 58 means payments into your late 80s unless you prepay or sell.
• If you're switching lenders at renewal. A straight switch with no increase in amortization or balance avoids the stress test at federally regulated lenders; extending the amortization means you'll be qualified as a new loan ^{[3] [5]}.

Step by step: extending your amortization with a broker

1. Decide how much relief you need, month by month, not the maximum available.
2. Ask your current lender whether it will re-amortize at renewal; some do, which can avoid refinance costs (our experience).
3. Get refinance quotes at 25 and 30 years, including legal, appraisal and any penalty.
4. Compare total interest for the schedule you'll really follow, using a table like the one above.
5. Choose a mortgage with strong prepayment privileges so you can step payments back up.
6. Set a date to review, for example in 12 or 24 months, and raise the payment when you can.

From our desk: the borrowers who come out ahead with a longer amortization set a reminder to raise the payment again, and many use the lower payment for a year or two, not 30.

Extending your amortization buys breathing room, and the cost depends on how long you keep it. Decide how much relief you need, compare total interest for the schedule you'll really follow, and build in a plan to pay more again.

Run your numbers: compare payments at 19, 25 and 30 years with our mortgage payment calculator, or read should I refinance my mortgage now or wait?

This article is for general information only and isn't financial, legal or tax advice. Rates, products and terms change without notice and are available on approved credit (OAC). The rate and terms you qualify for depend on your individual financial situation, including credit, income, property and loan-to-value. "Best rates" means the most suitable options available for your situation, not a guarantee of the lowest rate. Example rates and payments are for illustration only, as of October 2026, and are not an offer. 8Twelve Mortgage arranges mortgages through 65+ lenders and does not lend directly. Licensed across Canada — see our licences.

Example rates, payments and interest are for illustration only, as of October 29, 2026, and are not an offer; real rates change over time and at each renewal. Maximum amortizations, prepayment privileges and re-amortization at renewal vary by lender, OAC. Rules checked against FCAC and OSFI on October 29, 2026.