A bill is nothing more than a document requesting payment for goods or services rendered. For example, at a restaurant a waiter may present the bill which you pay with a credit card. When the month is over, the credit card company will send you another bill noting the restaurant charge. Bills are presented with the expectation of immediate payment (or within a specific amount of time, such as 30 days). When bills are not paid as agreed, they begin to incur finance charges and penalties and may even be sent to a collection agency. The total amount of a bill is often referred to as the balance due.