Assumable Mortgages in Canada: How a Mortgage Assumption Works
Updated
An assumable mortgage lets a buyer take over the seller’s existing mortgage, including its rate, balance and remaining term. When the seller’s rate is well below what new mortgages cost, both sides can come out ahead: the buyer keeps the lower rate for the rest of the term, and the seller doesn’t pay a penalty to break the mortgage. The catch is that the lender (and, for an insured mortgage, the insurer) must approve the new borrower, and the buyer needs enough cash or other financing to cover the seller’s equity. This page is part of our guide to mortgage types and features.
25-year amortization, semi-annual compounding. The saving lasts only as long as the assumed term.
How Much the Rate Gap Is Worth
The saving depends on the gap between the seller’s rate and the rate on a new mortgage. As a rough guide, each percentage point of gap is worth about $1,000 a year per $100,000 borrowed:
Seller’s Rate
New-Mortgage Rate
Savings Per $100K/Year
3-Year Savings on $500K
1.89%
5.49%
$3,600
$54,000
2.49%
5.49%
$3,000
$45,000
2.89%
5.49%
$2,600
$39,000
3.49%
5.49%
$2,000
$30,000
4.49%
5.49%
$1,000
$15,000
Simple interest on the starting balance; the real figure is a little lower because the balance falls.
The gap shrinks as low-rate mortgages reach maturity and as rates move, so the value of any particular assumption depends on today’s rates. Current offers are on our mortgage rates pages.
Benefits for Sellers
Benefit
Impact
No penalty to break the mortgage
The mortgage continues, so no prepayment charge applies
Marketing advantage
Attracts rate-conscious buyers
Faster sale
Appealing to buyers
Higher price possible
Buyers may pay a premium for a low rate
How large the avoided penalty would be depends on the rate and the contract. Breaking a closed mortgage, paying it off early or prepaying more than your privileges allow usually costs the higher of 3 months' interest and the interest rate differential (IRD) on a fixed rate, and typically 3 months' interest on a variable rate; your mortgage contract sets the exact method and comparison rate, and a federally regulated lender must tell you how it calculates the penalty. When the seller’s rate is below current rates, the interest rate differential is small, so the penalty is often close to three months’ interest: about $3,200 on $400,000 at 3.2% in the example above. The methods are explained in how mortgage penalties are calculated.
Same as a new mortgage (usually 680+ at A-lenders)
Debt ratios
Within the lender’s GDS and TDS limits
Income verification
Full documentation: employment letter, pay stubs, notice of assessment
Down payment
Enough to cover the seller’s equity
Property appraisal
The lender may require a new one
For an insured mortgage, CMHC caps your housing costs at 39% of gross income (GDS) and your housing costs plus other debt payments at 44% (TDS); lenders set their own limits for uninsured mortgages. How the ratios are calculated is in GDS and TDS ratios explained.
The Stress Test
A federally regulated lender usually applies the stress test to the buyer, as it would for a new mortgage; some credit unions and other lenders set their own policies, so it is worth confirming with the lender holding the mortgage. You qualify at the greater of your contract rate plus 2% or 5.25%. The full rule is in the mortgage stress test.
How to Assume a Mortgage
Step 1: Confirm the mortgage is assumable
Review the mortgage commitment or the mortgage document for an assumability or transferability clause
Contact the lender to confirm its assumption process
If the mortgage is insured, confirm the insurer’s requirements too
Step 2: The buyer applies
The buyer applies to the seller’s lender and qualifies as if for a new mortgage, as set out above. For an insured mortgage, the lender also submits the buyer to the mortgage insurer, which must approve the assumption.
Step 3: Approval (or denial)
If the lender approves, it issues an assumption approval. If it declines, the assumption can’t go ahead and the buyer needs other financing, which is why an offer conditional on the assumption needs a realistic condition period.
Step 4: Legal transfer
Both lawyers (or notaries) coordinate the transfer
The mortgage isn’t discharged; it remains registered on the property
The borrower on the mortgage changes to the buyer
Title transfers to the buyer as in a normal sale
Legal fees may be somewhat higher because of the extra work ($500-$1,000 extra)
Process Timeline
Step
Timeframe
Identify an assumable mortgage
During the house search
Make an offer with an assumption clause
Day 1
Apply to the lender for the assumption
Week 1-2
Lender reviews the application
Week 2-4
Approval or denial
Week 4-6
Closing
Upon approval
Documents Typically Required
For Buyer
For Transfer
Proof of income
Original mortgage documents
Credit report
Seller’s mortgage statement
Employment letter
Property appraisal
Down payment proof
Title documents
The Seller’s Liability: Getting a Written Release
Until the lender formally releases the original borrower, the seller may remain jointly liable for the mortgage. That means:
If the buyer defaults, the lender could pursue the seller
The mortgage keeps appearing on the seller’s credit report
The outstanding mortgage counts against the seller’s own borrowing capacity
A written release of the original borrower, as part of the assumption agreement, closes off that risk. A seller who isn’t released is still exposed for the rest of the term.
Handling the Equity Gap
The equity gap is the biggest practical obstacle. If a home is worth $700,000 and the assumable balance is $350,000, the buyer needs $350,000 in cash or other financing. Few buyers have that much, which is why second mortgages and seller financing often appear in assumption deals. The gap financing carries a higher rate, so the test is whether the combined cost of the assumed mortgage plus the gap financing still beats one new mortgage at current rates.
The Math
Factor
Amount
Purchase price
$700,000
Assumable mortgage balance
$350,000
Equity portion
$350,000
Buyer’s cash
$200,000
Gap to cover
$150,000
Ways to Cover the Gap
Option
How it works
Considerations
Cash from a property sale
Equity from selling the buyer’s current home
Timing must line up
Savings
Savings, TFSA or investments
Large cash requirement
Second mortgage
A separate lender registers behind the assumed mortgage
Higher rate (6-12%); must qualify for the combined payments
If the gap is covered mostly with expensive second-mortgage money, the combined payment can end up close to a single new mortgage, so the assumption’s advantage is largest when the buyer covers most of the gap in cash.
When an Assumption Works, and When It Doesn’t
Situation
Assumption benefit
Potential issue
Large rate gap (2 points or more)
Big payment and interest savings
Buyer needs more cash upfront
Several years left on the term
More value from the low rate
Few low-rate mortgages have long terms left
Buyer is selling another property
Sale equity covers the gap
Timelines must align
Purchase price close to the balance
Little extra cash needed
Rare: there is usually a gap
Small rate gap (under 1 point)
Minimal benefit
Often not worth the complexity
Small remaining balance
Little to gain
Not worth the process
Lender Policies and Fees
Lenders That Allow Assumptions
Lender Type
Assumptions
Most banks
Yes (with qualification)
Credit unions
Often yes
Monoline lenders
Varies
Private lenders
Usually yes
What Lenders Charge
Fee Type
Typical Amount
Assumption fee
$200-500
Legal review fee
$300-800
Credit check
$0-25
Total
$500-1,300
Risks and Considerations
Risks for Buyers
Risk
Mitigation
Lender denial
Apply early and keep a financing condition
Terms you inherit
Review all conditions, including prepayment terms
No rate negotiation
You take the seller’s rate as it is
Renewal at market rates
The low rate ends with the term
Risks for Sellers
Risk
Mitigation
Buyer doesn’t qualify
Alternative financing clause
Delays
Clear timelines
Still liable after the sale
A written release from the lender
Questions to Ask
Buyer’s questions
Seller’s questions
What is the rate, and how long is left on the term?
Will the lender allow an assumption?
What are the prepayment terms?
What would my penalty be if I broke the mortgage instead?
Can I add funds or change the term later?
Will I be fully released in writing?
Will the stress test apply?
What fees apply?
Alternatives to an Assumption
A seller who wants to keep a low rate can instead move it to their next home: porting a mortgage keeps the rate with the seller rather than passing it to the buyer. If the next home needs a larger mortgage, the lender typically blends the ported rate with today’s rate on the new funds, as shown in blended mortgage rates.
The Bottom Line
When a seller holds a low-rate mortgage and the buyer has the cash to cover the seller’s equity, an assumption can save tens of thousands of dollars over the remaining term compared with a new mortgage. Assumptions aren’t common in Canada and need lender (and insurer) approval, so they work best when both sides plan for them from the offer onward. A mortgage broker with assumption experience can help confirm the lender’s policy before an offer is made conditional on it.