When someone offers to help you make a down payment on a house, your lender will require a gift letter for a mortgage. Here's what it includes.How much money do you need to receive before a gift letter is necessary? A gift letter is a note from a donor to your lender regarding cash funds for your mortgage down payment. A gift letter is a piece of legal, written correspondence explicitly stating that money received isn't expected to be repaid. Provide Documentation:​​ Submit the gift letter, bank statements, and transfer confirmation during the mortgage approval process.