The letter must explain who is gifting the money, where the donor's funds are coming from and the relationship between the donor and the recipient. The purpose of this letter is to document that the money does not need to be repaid as well as the donor's name, contract information, and relationship to you.Mortgage Gift letter is what the donor of the gift writes to the lender stating that he has offered a gift of money to the home buyer. The most important document required is a gift letter. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment. The lender will need a "gift letter" from the donor to make sure your down payment help has no strings attached. A gift letter is one of the most important legal documents to prove the asset is yours. When using gift funds for a mortgage, a crucial step is to provide a gift letter. A gift letter from the donor to the recipient, detailing the amount gifted and its intended purpose. Your bank needs a written letter to prove that any money gifted to you to help buy a house is in fact a gift, not a loan.