What Is the Mortgage Stress Test?

The mortgage stress test is a federal rule that requires lenders in Canada to check whether you could still afford your mortgage payments if interest rates were meaningfully higher than the rate you're actually being offered. It doesn't change the rate you pay — it changes how much a lender will let you borrow in the first place.

How the qualifying rate works

To pass the stress test, you have to qualify at the higher of two numbers:

Your contract rate plus 2%, or
The minimum qualifying rate of 5.25%.

So if a lender offers you a 5-year fixed at 4.79%, you'll actually be qualified as though your rate were 6.79% (4.79% + 2%), because that's higher than 5.25%. If a lender offered you 3.00%, you'd be qualified at 5.25%, because 3.00% + 2% = 5.00% is lower than the floor.

Why it affects how much you can borrow

Lenders calculate your maximum mortgage based on the monthly payment at the qualifying rate, not your contract rate. A higher qualifying rate means a larger hypothetical payment, which eats into your allowed debt ratios and shrinks your maximum loan amount — often by tens of thousands of dollars.

The two ratios lenders check are:

GDS (Gross Debt Service) — housing costs (mortgage payment at the qualifying rate, property tax, heat, and half of condo fees) as a share of gross income. Typically capped around 39%.
TDS (Total Debt Service) — GDS plus all other debt payments (car loans, lines of credit, credit cards, student loans). Typically capped around 44%.

Who has to pass it

The stress test applies to all federally regulated lenders — the big banks, most credit unions that opt in, and most monoline lenders. It applies whether you're buying a first home, refinancing, or switching lenders at renewal. Some provincially regulated credit unions are technically exempt, but most apply their own version of the rule.

What you can do to improve your position

Pay down high-interest debt first. Every dollar of monthly minimum payment on a credit card or line of credit directly reduces the mortgage you qualify for.
Extend your amortization. A 30-year amortization instead of 25 lowers the qualifying payment and increases the loan amount. Insured mortgages can now go up to 30 years for first-time buyers or new builds.
Add a co-signer or co-borrower. More qualifying income means higher allowable ratios.
Increase your down payment. A larger down payment reduces the loan and the qualifying payment.
Shop through a broker. Brokers can compare stress-tested affordability across many lenders at once, including some with slightly more flexible policies on bonuses, self-employment income, or rental offsets.

The bottom line

The stress test isn't a penalty — it's a buffer designed to make sure a rate hike doesn't push you into default. But it does mean the mortgage you qualify for is almost always smaller than the mortgage you could technically afford at today's rate. Knowing the math up front lets you plan a realistic price range before you start shopping.