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. If you go through a bank they will provide the gift letter form to you to get completed.If someone provides a handwritten letter it is filed away. A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. The lender is requiring me to write a gift letter stating I'm gifting my SO the down payment, with no expectation of being repaid. A gift letter is a document stating that any money received from family or friends is a cash gift and not a loan. Go back to that mortgage officer, and tell him it's a gift. Ask him what he needs in the way of documentation to show it's a gift, not a loan. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment.