The Guideline, Residential Mortgage Underwriting Practices and Procedures (B-20), builds on the Financial Stability Board’s international Principles for Sound Residential Mortgage Underwriting Practices (released in April 2012) and OSFI’s own domestic supervisory work. The final Guideline is the result of a thorough consultation process; a summary of comments received and OSFI’s responses to them is provided in an annex to the covering letter.