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. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment.Use our mortgage gift letter 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 short letter like this sample gift letter will cover all of the requirements your lender needs. Here's a sample gift letter you can use to prove that the money is truly meant as an outright gift, with no expectation of repayment. How to Write a Gift Letter for a Mortgage Down Payment? Go back to that mortgage officer, and tell him it's a gift. Ask him what he needs in the way of documentation to show it's a gift, not a loan.