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. Yes, all lenders will require a gift letter.Although you may have the funds, the lender needs to confirm that you won't have to repay the gift. A mortgage gift letter is a document that helps satisfy the requirement that a borrower's down payment funds come from legitimate sources. 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. If you're looking to use a gift letter from your family to fund a down payment, make sure you have the legal documentation necessary.