What the stress test actually is
The stress test is an affordability rule from Canada's banking regulator, OSFI. Instead of qualifying you at your real contract rate, lenders must check that you could still afford the payments at a higher 'qualifying rate.'
The qualifying rate is the greater of your contract rate plus two percentage points, or the 5.25% minimum floor. So a 4.4% contract rate is tested at 6.4%; a 3.0% rate is tested at 5.25%.
How it shrinks your maximum mortgage
Because lenders run your debt ratios at the higher qualifying rate, your maximum approved mortgage is smaller than your contract rate alone would allow — frequently by 15–20%.
Your approval hinges on two ratios: GDS (housing costs as a share of gross income) and TDS (all debt payments as a share of gross income). Most lenders look for GDS under about 39% and TDS under about 44%, calculated at the qualifying rate.
Who has to pass it
The test applies to new purchases, refinances, and most transfers to a new federally regulated lender. One important nuance: if you simply renew with your existing lender, you generally do not have to requalify under the stress test.
That is why shopping at renewal can be a trade-off — switching lenders may get you a better rate but can require passing the test again, while staying put avoids it.
How to pass it
If the numbers are tight, you have several levers, and small changes to your debts often move your approval more than you expect.
- Pay down or eliminate car loans, lines of credit, and credit-card balances — they hit your TDS directly.
- Increase your down payment to reduce the mortgage amount you need to qualify for.
- Consider a longer amortization (up to 25 or 30 years) to lower the qualifying payment.
- Add a strong co-applicant, or shop a wider set of lenders, since debt-ratio thresholds vary.