# What does OSFI's Guideline B-20 say about mortgage lending?

> Guideline B-20 outlines OSFI's expectations for responsible residential mortgage underwriting.

Category: Renewal
Last verified: 2026-02-18
Source: https://ratellow.com/faqs/renewal/what-does-osfis-guideline-b-20-say-about-mortgage-lending

## Answer
OSFI's B-20 guideline key focus areas:

* Borrower assessment (income, debt service coverage, net worth, living expenses).
* Collateral management (property appraisals).
* Risk management (mortgage insurance).

## Institutional highlights
- These rules apply to all banks and lenders in Canada that offer mortgages.
- Lenders must ensure you're both willing and able to repay your mortgage, and that the value of your home covers the loan.
- When you apply for a mortgage, lenders will look at your overall financial situation to determine if you can comfortably afford your payments.
- Your lender might require mortgage insurance, which can be provided by the government or private companies.
- Lenders are responsible for checking that any mortgage insurance company they use is financially stable and reliable.

## Related guide
- https://ratellow.com/guides/refinance-extend-amortization

## Sources
- Property appraisals — https://www.osfi-bsif.gc.ca/en/guidance/guidance-library/residential-mortgage-underwriting-practices-procedures-guideline-2017#2.4.2
- I. Purpose and scope of the guideline — https://www.osfi-bsif.gc.ca/en/guidance/guidance-library/residential-mortgage-underwriting-practices-procedures-guideline-2017#1.0
- Mortgage insurance — https://www.osfi-bsif.gc.ca/en/guidance/guidance-library/residential-mortgage-underwriting-practices-procedures-guideline-2017#2.5.1