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 gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. The purpose of this letter is to document that the money does not need to be repaid as well as the donor's name, contract information, and relationship to you. Mortgage Lenders Require Gift Letters. A gift letter for a mortgage is a written statement confirming that the gift money you receive from a family member or friend is a gift, not a loan. A gift letter is a document that certifies the funds you're receiving for your down payment are a gift, not a loan. Step 2 – Fill in the details of the donor. You must provide the following details of the "donee", i.e. If their gift is too large, they may have to fill out a gift tax form when filing returns.