A mortgage stress test verifies that you are able to pay off your mortgage at the “minimum qualifying rate.” This rate is usually higher than the rate you receive in your mortgage contract. The banks will conduct the “test” using a 5.25% interest rate or your negotiated interest rate plus 2%. Stress testing your mortgage determines your home's affordability. All Canadian home buyers who obtain their mortgage from a federally-regulated bank are required to pass a mortgage stress test (even if you are exempt from paying mortgage loan insurance).