A mortgage proposal letter is a formal document that provides details of the terms and conditions for a potential mortgage between a lender and a borrower. It outlines the rate of interest, repayment schedule, penalties for late payments, and other important information related to the loan. The purpose of a mortgage proposal letter is to provide clarity and transparency so that both parties can agree to the terms with full understanding of the consequences. A well written mortgage proposal letter can help ensure a successful and beneficial outcome for both parties.