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. What should the gift letter include?The goal of a gift letter is to provide the lender with proof of where the funds came from. 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 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. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment. The letter will also need to explain your relationship to the donor. The person giving the gift must complete and sign the letter.