Negative amortization is when your mortgage balance goes up instead of down, even though you are making every payment on time. It is the exact opposite of what a mortgage is supposed to do. Instead of building equity with each payment, you are losing it — and the longer it continues, the deeper the hole gets.
This became a major issue for Canadian homeowners during 2022–2023, when the Bank of Canada raised the overnight rate from 0.25% to 5.00% in the fastest hiking cycle in decades. Hundreds of thousands of variable-rate mortgage holders with fixed payments found that their payments no longer covered the interest on their mortgages. The unpaid interest was silently added to their balances month after month.
How Negative Amortization Works
The Mechanics
In a normal mortgage payment:
Payment = Interest Portion + Principal Portion
In negative amortization:
Payment < Interest Owed → Shortfall Added to Principal
Month-by-Month Example
| Month | Balance | Interest Owed (5.75%) | Payment | Principal Paid | Balance Change |
|---|---|---|---|---|---|
| 1 | $450,000 | $2,156 | $1,950 | -$206 | +$206 |
| 2 | $450,206 | $2,157 | $1,950 | -$207 | +$207 |
| 3 | $450,413 | $2,158 | $1,950 | -$208 | +$208 |
| 6 | $451,242 | $2,162 | $1,950 | -$212 | +$212 |
| 12 | $452,710 | $2,169 | $1,950 | -$219 | +$219 |
Based on $450,000 mortgage, 5.75% variable rate, payment originally set at 3.20% rate.
After 12 months of negative amortization, this borrower owes $2,710 more than they started with — despite making $23,400 in payments over the year. None of that money touched the principal.
How It Compounds
The problem gets worse over time because the unpaid interest earns its own interest:
| Period | Balance Increase | Cumulative Extra Owed |
|---|---|---|
| After 6 months | $1,242 | $1,242 |
| After 12 months | $2,710 | $2,710 |
| After 24 months | $5,980 | $5,980 |
| After 36 months | $9,900 | $9,900 |
Why It Happens: Fixed-Payment Variable-Rate Mortgages
The Two Types of Variable-Rate Mortgages in Canada
| Type | Payment Behaviour | Negative Amortization Risk |
|---|---|---|
| Fixed-payment variable | Payment stays the same; only the interest/principal split changes | High — if rates rise enough, payments can’t cover interest |
| Adjustable-payment variable | Payment changes with every rate change | None — payment always covers full interest + principal |
Which Banks Use Which Type
| Lender | Variable Mortgage Payment Type |
|---|---|
| TD | Fixed payment (adjustable on request) |
| CIBC | Fixed payment |
| BMO | Adjustable payment |
| RBC | Adjustable payment |
| Scotiabank | Adjustable payment |
| National Bank | Fixed payment |
If you have a variable-rate mortgage with TD, CIBC, or National Bank, your payment is likely fixed — meaning you are vulnerable to negative amortization when rates rise. If you have a variable with BMO, RBC, or Scotiabank, your payment adjusts automatically, so you always cover the interest.
How Much Rates Need to Rise
The threshold depends on the difference between your original rate and the current rate:
| Original Rate (When Mortgage Set Up) | Rate That Triggers Negative Amortization | Rate Increase Needed |
|---|---|---|
| 1.50% | ~3.40%+ | ~1.90% |
| 2.00% | ~3.90%+ | ~1.90% |
| 2.50% | ~4.40%+ | ~1.90% |
| 3.00% | ~4.90%+ | ~1.90% |
| 3.50% | ~5.40%+ | ~1.90% |
Approximate — exact trigger varies by amortization length and specific payment schedule.
During the 2022–2023 cycle, rates rose by 4.75 percentage points. Borrowers who locked in variable rates at 1.50%–2.50% during 2020–2021 didn’t just hit negative amortization — they blew through it by a wide margin.
The 2022–2023 Crisis: What Actually Happened
The Timeline
| Date | Bank of Canada Rate | Typical Variable Mortgage Rate | Status |
|---|---|---|---|
| January 2022 | 0.25% | 1.40%–1.70% | Normal amortization |
| March 2022 | 0.50% | 1.65%–1.95% | Normal amortization |
| July 2022 | 2.50% | 3.65%–3.95% | Approaching trigger rate |
| October 2022 | 3.75% | 4.90%–5.20% | Negative amortization begins for most |
| January 2023 | 4.50% | 5.65%–5.95% | Deep negative amortization |
| July 2023 | 5.00% | 6.15%–6.45% | Maximum negative amortization |
Impact by the Numbers
| Metric | Estimate |
|---|---|
| Canadians with variable-rate mortgages | ~1.4 million |
| Percentage on fixed-payment variable | ~60% (~840,000) |
| Estimated number in negative amortization (peak) | ~500,000–600,000 |
| Average amortization extension | 10–30+ years (some exceeding 70 years) |
Some borrowers saw their amortizations balloon from 25 years to 65 or even 90+ years on paper — a mathematical consequence of payments barely covering (or not covering) the interest.
Five Ways Out of Negative Amortization
1. Increase Your Regular Payment
Most mortgages allow you to increase your payment by 10–25% annually using your prepayment privilege — no penalty, no approval needed.
| Current Payment | 20% Increase | New Payment | Cost vs Interest? |
|---|---|---|---|
| $1,950 | +$390 | $2,340 | Covers interest ($2,156) + $184 principal |
This is the simplest and cheapest option. Call your lender and request a payment increase. Ensure the new payment exceeds the monthly interest charge.
2. Make a Lump Sum Payment
Use your annual lump sum prepayment privilege (typically 10–20% of original mortgage amount) to reduce the balance directly.
| Lump Sum | Effect on Balance | Annual Interest Savings |
|---|---|---|
| $10,000 | Balance drops $10,000 | ~$575 |
| $25,000 | Balance drops $25,000 | ~$1,438 |
| $50,000 | Balance drops $50,000 | ~$2,875 |
A lump sum reduces the principal, which reduces the monthly interest charge, which makes it easier for your fixed payment to cover the interest again.
3. Switch to a Fixed Rate
Your lender may allow you to convert from variable to fixed mid-term — but this comes with trade-offs:
| Consideration | Details |
|---|---|
| Rate | You will likely get the lender’s posted fixed rate (higher than discounted) |
| Penalty | Some lenders charge a penalty; others convert at no cost |
| Lock-in risk | If rates are about to fall, locking in fixed defeats the purpose |
| Term | Usually matches remaining variable term |
Ask your lender for the conversion rate and any associated costs before deciding. If variable rates are expected to decrease significantly, waiting may be more cost-effective than locking in a high fixed rate.
4. Refinance the Mortgage
Breaking the mortgage entirely and refinancing gives you a clean start — new rate, new term, potentially new lender.
| Factor | Details |
|---|---|
| Penalty | 3 months’ interest (variable rate) |
| Legal and administrative fees | $500–1,500 |
| Benefit | New market rate; new payment that definitely covers interest |
| When it makes sense | Your current lender’s conversion rate is uncompetitive |
The penalty on breaking a variable-rate mortgage is always 3 months’ interest — much less than fixed-rate IRD penalties. This makes refinancing a viable option.
5. Wait for Rates to Decrease
If the Bank of Canada is cutting rates, your variable rate will decrease, and eventually your fixed payment will again cover the full interest — and then start reducing principal.
| Rate Cut | Effect on Monthly Interest ($450,000) | Payment Covers Interest? |
|---|---|---|
| Rate drops to 5.25% | $1,969 | Yes ($1,950 is close) |
| Rate drops to 4.75% | $1,781 | Yes — with $169 going to principal |
| Rate drops to 4.25% | $1,594 | Yes — with $356 going to principal |
Risk: Waiting means your balance continues to grow in the meantime. If rates don’t fall as quickly as expected, you take on more debt for longer.
Trigger Rate vs Trigger Point
These two terms are related but different:
| Concept | Definition | What Happens |
|---|---|---|
| Trigger rate | The interest rate at which your entire payment goes to interest (0% to principal) | You are at the threshold — one more increase and you are negatively amortizing |
| Trigger point | The point where your outstanding balance exceeds a percentage of your home’s original value (varies by lender, often 65–80%) | Your lender contacts you and requires action |
For detailed explanations, see mortgage trigger rate explained and trigger point options.
How to Check If You Are in Negative Amortization
Method 1: Check Your Mortgage Statement
| What to Look For | Interpretation |
|---|---|
| Original principal | What you started with |
| Current principal | What you owe now |
| Current > Original | Negative amortization is occurring |
Method 2: Ask Your Lender
Contact your lender and ask:
- “Is my current payment covering the full interest charge?”
- “What is my effective amortization?”
- “Have I hit my trigger rate?”
Method 3: Do the Math
Monthly Interest = (Outstanding Balance × Annual Rate) ÷ 12
If this number is higher than your monthly payment, you are in negative amortization.
Example: $450,000 × 5.75% ÷ 12 = $2,156/month in interest. If your payment is $1,950, you are short $206/month.
Long-Term Consequences of Ignoring Negative Amortization
| Consequence | Impact |
|---|---|
| Extended amortization | 25-year mortgage could stretch to 35, 40, or 50+ years |
| Higher balance at renewal | Owe more at renewal than when you started |
| Potential trigger point breach | Lender forces action — payment increase or lump sum |
| Reduced equity | If home values drop, you could be underwater |
| Higher renewal payments | Significantly increased payments when you renew at a new term |
| Total interest cost | Thousands to tens of thousands more over the mortgage life |