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. If you go through a bank they will provide the gift letter form to you to get completed.If someone provides a handwritten letter it is filed away. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment. A mortgage gift letter is a document that helps satisfy the requirement that a borrower's down payment funds come from legitimate sources. A gift letter is a letter stating that money you receive from a friend or family member is in fact a gift, not a loan. Before a lender allows the gift, you'll also need to furnish a gift letter that states the name, address, and phone number of the donor.