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.A short letter like this sample gift letter will cover all of the requirements your lender needs. 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. Learn how to create a mortgage gift letter template to ensure a smooth homebuying process with your gifted funds with 6 samples. 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 gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. A gift letter is an important, formal, legal piece of documentation that can help explain that a (usually rather large) sum of money was gifted to you.