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 is an important, formal, legal piece of documentation that can help explain that a (usually rather large) sum of money was gifted to you.A mortgage gift letter is a statement that assures your lender the money that came into your account is a gift and not a loan. Your parents will need to file the proper forms with IRS declaring the gift. So no potential consequences of gift tax. A signed gift letter from her parents. A gift letter needs to be from the person who gave you the funds, and they need to include information showing the gift doesn't need to be paid back. 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. Today's Date: Medi-Cal Access Program. A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment.