Canada mortgage stress test: OSFI B-20, CMHC insurance, and GDS/TDS

Understand Canada's mortgage qualification rules, the OSFI Guideline B-20 qualifying rate, CMHC default insurance, and GDS/TDS debt ratio ceilings.

Updated 2026-08-26 · Reviewed against OSFI Guideline B-20 and Financial Consumer Agency of Canada regulations. · Fact-Checked Lending Norms

The OSFI B-20 qualifying stress rate

Federally regulated financial institutions must qualify borrowers at the higher of the contractual mortgage rate plus 2.0 percentage points or the minimum benchmark rate of 5.25%. This prevents default when interest rates fluctuate.

GDS and TDS debt ratio ceilings

Lenders evaluate Gross Debt Service (GDS, mortgage + property taxes + heating + 50% condo fees) capped at 32% (or up to 39% for prime credit) and Total Debt Service (TDS, all housing plus student loans, credit cards, and auto financing) capped at 40% to 44% of gross income.

High-ratio mortgages and CMHC insurance

Purchases with less than 20% down (up to the $1.5M ceiling) require mortgage default insurance backed by CMHC, Sagen, or Canada Guaranty. Premiums range between 2.80% and 4.00% of the loan amount, capitalized into your total financing.

5-year fixed vs 5-year variable terms

Canadian mortgages are typically structured with a 25-year amortization schedule broken into 3-year or 5-year loan terms that require refinancing or renewal at prevailing market rates upon maturity.

ℹ️ Statutory Notice & Methodology

Global Finance Calculator provides mathematical estimates for education, planning, and comparison — not regulated financial advice or credit pre-approval. Tax legislation, statutory central bank buffers, and underwriting criteria change. Confirm critical figures with official regulatory publications or a licensed mortgage broker before signing contracts.