What amortization means in plain English
Amortization is the total number of years it would take to pay off your mortgage assuming the rate and payment never change.
Term is different — your term is the length of time you're locked into the current rate (usually 5 years). When your term ends, you renew at whatever the new rate is, but the amortization timer keeps counting down. A 25-year amortization with five 5-year terms means you renew four times before it's fully paid off.
Think of amortization as the size of the marathon. Term is the segment between aid stations.
The math at typical Canadian rates
Take a $720,000 mortgage at 4.84% (Canadian semi-annual compounding):
| Amortization | Monthly P&I | Total over amortization | Interest paid | |---|---|---|---| | 20 years | $4,672 | $1,121,300 | $401,300 | | 25 years | $4,124 | $1,237,200 | $517,200 | | 30 years | $3,810 | $1,371,600 | $651,600 | | 35 years (rare) | $3,617 | $1,519,100 | $799,100 |
Going from 25 to 30 years saves $314/month but adds $134,400 in lifetime interest. The longer you amortize, the slower equity builds and the more interest you pay.
Why the interest difference is so big
In the early years of a mortgage, almost the entire payment goes to interest. A 30-year amortization stretches that "front-loaded interest" phase by another 5 years — meaning the first 60 payments after year 25 are still mostly interest, just at a lower balance.
Run your own scenario in the amortization schedule calculator.
When 25 vs 30 years matters most
Qualifying ceiling
The federal stress test caps your qualifying payment based on income. A 30-year amortization stretches the payment over 60 more months, dropping the monthly number — meaning you qualify for a larger mortgage. This is the primary reason 30-year insured amortization was reintroduced in August 2024 for first-time new-build buyers.
Worked example — household income $130k/yr, $400/mo other debt:
- Max insured mortgage at 25-year amortization (5.49% qualifying): ~$540,000
- Max insured mortgage at 30-year amortization: ~$590,000
- Lift: $50,000 more mortgage qualifying
Monthly cashflow
If you're stretching at the affordability ceiling, that $300-$400/month is the difference between "we can buy" and "we have $0 left at end of month." Choose 30-year for the breathing room.
Investment opportunity cost
The classic counter-argument to 25-year is: invest the monthly savings instead. At a 6%/yr return, $314/mo invested for 30 years compounds to ~$315,000 — more than the extra interest paid. The math holds if you actually invest the difference. Most people don't.
If the alternative to a 30-year amortization is investing the savings into a TFSA, the math favours 30-year. If the alternative is buying more car / coffee / vacations, choose 25-year and force the savings.
The 2024 30-year insured rule
As of August 1, 2024, Canadian first-time home buyers of newly built homes can qualify for a 30-year insured amortization. The rule:
- Must be a first-time buyer (you + spouse haven't owned in 4+ years)
- Property must be a brand-new build (not resale, not assignment from prior owner)
- Mortgage must be insured (CMHC, Sagen, or Canada Guaranty)
Most major Canadian lenders participate. See our 30-year amortization for new builds guide for full details.
Uninsured (20%+ down) amortization options
If you put down 20% or more, the federal insurance rule doesn't apply, and lenders can offer longer amortization at their own discretion:
- Most banks + monolines: up to 30 years standard
- Some banks: up to 35 years on high-net-worth files
- Credit unions: occasionally 35 years
- Alt-A / private lenders: rare to see > 30 years
Uninsured rates are typically 20-50 bps higher than insured equivalents, so the math comparison isn't always favourable.
The recapture strategy
If you take a 30-year amortization for affordability or cashflow reasons, you can claw back almost all the lost equity by aggressive prepayments:
Lump-sum prepayments
Most A-tier closed mortgages allow 15-20% of original principal in lump-sum prepayments per year, penalty-free. On a $580,000 mortgage that's $87,000-$116,000/yr of optional prepayment capacity.
Payment increases
Same mortgages typically allow 15-20% payment increases per year. Going from $3,810/mo to $4,572/mo (a 20% boost) effectively converts a 30-year amortization back to ~24 years.
Annual bonus / tax refund hit
Common pattern: take 30-year amortization for stress-test wiggle room, then drop a $5k-$15k lump sum every year from bonus or tax refund. Cuts the amortization back to 23-24 years in practice.
Run the math in the prepayment savings calculator.
How amortization interacts with renewal
At renewal, you don't restart the amortization timer — it just keeps counting down. A 25-year amortization renewed after a 5-year term has 20 years remaining; renewed after 10 years has 15 years remaining.
Many borrowers re-amortize at renewal to lower their monthly payment, especially if life has gotten more expensive. This RESETS the amortization clock and re-stretches the interest cost. Only do it if you actually need the cashflow.
Common questions
Can I change my amortization mid-term?
Generally no — your contract sets the amortization for the term. At renewal, you can negotiate a new amortization period (often shorter, sometimes longer) with your lender or a new lender.
Does paying extra change my amortization?
Yes, but in two different ways. Lump-sum prepayments and payment increases reduce the amortization implicitly — you'll pay it off faster. They don't, however, shorten the contractual amortization on paper unless your lender formally re-amortizes you (typically at renewal).
Is a shorter amortization always better?
Yes mathematically (less interest), but not always practically. If a 25-year amortization is the difference between qualifying for the home you want and not, take 30 years and accelerate later.
What's the most common Canadian amortization?
25 years on insured mortgages (pre-2024 era). 30 years is increasingly common since August 2024 for first-time buyers of new builds.
Can I get a 30-year amortization on a resale home?
Only if you have 20%+ down (uninsured) and your lender allows it. First-time buyers of resale homes are still capped at 25-year insured.
Bottom line
Amortization is a powerful lever — second only to the rate itself in long-term cost impact. The right choice depends on:
- Whether you need the qualifying boost (favours 30-year)
- Whether your budget has slack (favours 25-year)
- Whether you'll actually invest the monthly savings (favours 30-year)
- Whether you plan to aggressively prepay later (either works)
Run your specific scenario in the mortgage payment calculator toggling amortization, then layer in prepayment plans via the prepayment savings calculator.
Related reading: 30-year amortization for new builds, Prepayment savings, Bi-weekly vs monthly.