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. Most importantly, the gift letter must specify that funds are a gift and not a loan.In order to properly document and complete their down payment gift, the donor should: Write an official gift letter (see above for details). The solution is to ask for a gift letter to accompany any large financial gift you use for your down payment. Earnest Money Check–cancelled check copy; Gift Letter and Documentation (if applicable). Makes your offer nearly as good as gold. Update: I ended up paying cash with no mortgage. First Heritage Mortgage, LLC.