The federal mortgage stress test requires you to qualify at a higher interest rate than the one you’ll actually pay — specifically, the higher of your contract rate plus 2%, or the Bank of Canada’s benchmark qualifying rate (currently 5.25%). This applies to virtually all mortgages in Canada, insured or not.
The stress test doesn’t change your actual monthly payment — you’ll still pay at your real contract rate — but it does reduce the maximum mortgage amount you can qualify for, since lenders need to confirm you could still afford the payments if rates rose. It’s one of the most common reasons a buyer’s approved amount comes in lower than they expected.