Your payment rate and your qualifying rate serve different purposes. Learn which figure drives the ratios and what to check before comparing scenarios.
One mortgage, two different rates
The contract rate is the rate agreed for the mortgage. The qualifying rate is used to calculate the payment for affordability assessment. A stress test asks whether the borrower could support a higher payment; it does not add two percentage points to the GDS or TDS limit.
A calculator can therefore display one contractual payment and a larger payment inside its qualification calculation. Before comparing two tools, check the rate, mortgage amount, amortization, compounding and payment frequency used for each figure.
Check both the buffer and the floor
For uninsured mortgages covered by its prescribed minimum qualifying rate, OSFI currently uses the higher of contract rate plus two percentage points or 5.25%. The rate is reviewed periodically, so check the current OSFI rule for the application.
- At a 4.00% contract rate, the buffer gives 6.00%, which is above the 5.25% floor.
- At a 3.00% contract rate, the buffer gives 5.00%, so the floor makes the prescribed qualifying rate 5.25%.
Those are rate examples, not offers. A lender-specific setting is appropriate only when its program permits that treatment.
Why the ratios move
Imagine gross qualifying income of $10,000 a month, housing costs calculated at the contract rate of $3,000, and other debt payments of $500. The illustrative ratios are 30% GDS and 35% TDS.
If using the qualifying payment increases those housing costs to $3,400, the same file becomes 34% GDS and 39% TDS. Income and other debts have not changed; the $400 payment difference accounts for both four-percentage-point increases.
Compare a change in rate separately from a change in amortization. Otherwise, a lower payment can hide the effect of a longer repayment period.
Do switches always need the same test?
Some eligible uninsured straight switches at renewal are exempt from OSFI’s prescribed minimum qualifying rate. Eligibility and the receiving lender’s underwriting still matter. See our refinancing and switch guide for the transaction conditions. Selecting Off in a calculator does not establish that a deal qualifies for an exemption.
Set the actual qualifying rate in the calculator
- Enter the contract interest rate and amortization in MyMortgageMate.
- With Stress Test On, the editable qualifying rate starts at contract plus two. Confirm it meets the applicable lender rule, including any minimum floor. For the 3.00% example above, manually enter 5.25% where the prescribed rule applies.
- A manual qualifying-rate override stays in place until you change the contract rate. A contract-rate edit resets it to the new rate plus two, so recheck any required floor or program override.
- Stress Test Off models the contract rate. Use it only for the basis you intend to assess; it is not an approval decision.
- Check each editable scenario’s own qualifying rate, then review the printed synopsis.
Record why a custom rate was used so another reviewer can reproduce the figures.
Put the figures into a scenario
Use the appropriate assumptions, compare the results and save a summary for your file.
Open the Residential Calculator →Sources and review
References checked September 22, 2026. Examples are illustrative; confirm the lender, insurer and program requirements for your situation.