A down payment is a partial payment given in order to show intent of purchase. When you intend to make a purchase of an item but do not have the means to pay in full or if a full upfront payment is not required, a down payment may be. A down payment can be a set amount or percentage that is agreed upon by the purchaser and the seller for the intent to purchase the item in full. In most cases, there is a contract outlining the partial down payment and then when everything is due in full.