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. 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.FHA loans allow gift funds to be used on primary residences only. A gift letter is a document that overviews and outlines the terms of a down payment gift for a real estate purchase. You can use gifted funds to make a down payment, but your mortgage lender will want to know some details before they allow you to use it.