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 A short letter like this sample gift letter will cover all of the requirements your lender needs. What should you include in a gift letter? If you use a gift payment, you'll need a gift letter for the mortgage if the gift is made within three months of the closing. This guide explains how to document gift funds for a mortgage and meet lender requirements. A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment.