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 for a mortgage shows your lender that you don't need to repay gift money toward your down payment.A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. This guide explains how to document gift funds for a mortgage and meet lender requirements. 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 piece of legal, written correspondence explicitly stating that money received isn't expected to be repaid. Below you'll find a list of some general questions. If you're experiencing problems with online banking or our apps, first check here for solutions. Upload your Form Online. Log in to your American Express Savings account.