A money order is a certified backed by cash and issued by a government or banking institution. They can be purchased at a number of locations for a small fee. A money order is cash on delivery. Some government agencies require particular types of payments that are backed by cash (i.e., cashier’s check and money order). Money orders must be paid with a debit card or cash. Personal checks and credit cards are not valid forms of payment since they are not backed by guaranteed cash and can be canceled after the money order has been purchased.