Genworth Financial Canada recently tightened several of its credit rules for insured mortgages in and cut both its credit assist and high-ratio rental programs - further signs that non-A borrowers might have bigger challenges in the current market.

"Genworth's portfolio may be scrutinized a bit more because of having only 90% government backing and that scrutiny is probably why they're tightening up their guidelines," said Darick Battaglia, a broker with Dominion Lending Centres in Barrie, Ont. "They have to prove to the investor market that what they're putting in the market is something investors can feel more secure with."

Among the new guidelines is a beacon score requirement for people buying units in highrise condos (more than four floors), as well as increased credit scores for self-employed borrowers (for example, a beacon score increase from 650 to 700 for 85% to 90% loan-to-value ratios).

In a statement, Genworth wrote, "Genworth Financial Canada is committed to insuring quality loans that make sense for everyone ... Our recent product and guideline changes are a direct response to this and are intended to help Canadians purchase and refinance homes they can afford now as well as in the future."