Mortgage stress test
The BrokerFold Team — Product + Engineering
Last reviewed
The mortgage stress test is Canada’s rule that borrowers must qualify not at the interest rate they’ll actually pay, but at a higher qualifying rate — the greater of a regulatory floor rate and their contract rate plus a two-point buffer. Federally regulated lenders apply it to uninsured mortgages under OSFI’s B-20 guideline; a parallel rule covers insured mortgages. The point is resilience: proving the household survives a rate shock before it borrows.
What it changes in practice
The stress test converts “what payment can I afford?” into “what payment could I afford if rates jumped?” — and sizes the loan to the second answer. That’s why a pre-approval ceiling is lower than the sticker-rate arithmetic suggests, why falling contract rates don’t loosen budgets one-for-one (the floor rate can bind instead), and why buyers comparing lenders should ask about the qualifying rate, not just the offered rate. Borrowers who can’t pass at a bank sometimes migrate to provincially regulated or alternative lenders where the guideline doesn’t reach — usually paying for the privilege.
The moving parts to respect
The floor number, the buffer, and the renewal-switch treatment are policy dials that regulators have adjusted repeatedly and will again. Quote the mechanism confidently; verify the current numbers the week you need them. Anything more specific in print ages badly — which is itself worth telling clients.
Why it matters for your practice
The stress test is the invisible hand inside every buyer’s budget conversation. Explaining it plainly — mechanism, not memorized numbers — is how an agent turns “the bank approved less than we hoped” from a mystery into a plan.
Frequently asked questions
Does the stress test apply to renewals?
Renewing with your existing lender generally doesn't re-trigger it, which keeps borrowers mobile-in-place. Switching lenders at renewal has been the policy battleground: rules here have shifted in recent years toward easing straight switches on insured and standard loans — confirm the current treatment with your broker rather than assuming either way.
How much does the stress test cut buying power?
Qualifying roughly two points above your contract rate typically trims maximum affordability by a double-digit percentage — the exact haircut depends on rates, income, and amortization. The practical translation: the pre-approval ceiling already has the stress test inside it, so bidding at that ceiling is genuinely bidding your maximum.
Keep reading
- Pre-approval vs pre-qualification Pre-qualification is an estimate from stated numbers; pre-approval is underwritten and rate-held. Which one means anything in an offer, and why.
- CMHC insurance Mortgage default insurance — required under 20% down — protects the lender, costs the borrower a premium, and unlocks high-ratio buying. The mechanics.
- Bridge financing Bridge financing is a short-term loan covering the gap when you close a purchase before your sale — how it works, what it costs, and its limits.