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. 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.We'll also show you how to write a gift letter with a gift letter template so you can help your donor prepare for underwriting. 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. A mortgage gift letter is a document that helps satisfy the requirement that a borrower's down payment funds come from legitimate sources. A mortgage gift letter is a document that helps satisfy the requirement that a borrower's down payment funds come from legitimate sources. Close-up of gift details on form. The letter should include the exact dollar amount of the gift and the date of transfer. Gift letter template for mortgage down payment gift.