BILL, in Commerce, denotes a security for money under the hand and sometimes seal of the debtor, without any condition or forfeiture in case of non-performance; in which it is distinguished from a bond or obligation. It has been usually defined, a writing wherein one man is bound to another to pay a sum of money, on a day that is future, or presently on demand, according to the agreement of the parties at the time when it is drawn; on which, in case of failure, diligence or execution may be immediately done to force payment. These bills must be on stamped paper: if under 50l. the stamp to be 6d.; if for 50l. or upwards 1s.