A colloquialism in real estate, a Jingle Mail is the letter a lender would receive containing a borrower’s keys (making a “jingle” sound as the keys bounced around). This situation typically occurs when there is a sharp decrease in the market value of property, such as occurred during the 2008 subprime mortgage crisis. Jingle Mail generally refers to a Deed in Lieu of Foreclosure and in many parts of the world is also called “giving back the keys.”