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. Here are the top things you need to know when receiving mortgage down payment gift funds.Bonus: download a free gift letter template. A gift letter for a mortgage shows your lender that you don't need to repay gift money toward your down payment. A mortgage gift letter is a document that helps satisfy the requirement that a borrower's down payment funds come from legitimate sources. A gift letter is a letter stating that money you receive from a friend or family member is in fact a gift, not a loan. A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. A gift letter should include the name and contact information of the donor and a statement that no repayment is expected. Please also provide proof of down payment or gift letter.