A paper instrument (document) used in overseas trade. An unconditional order guaranteeing that monies will be paid at some future time or paid upon completion of certain terms (eg receipt of goods). Usually struck for high financial amounts to govern international shipments.
A form of very clever contract and an I.O.U all rolled into one. Its most common form is a commitment to pay money upon receipt of goods by a foreign customer. For example, a Bill could say:- 'Pay to the order of Mr X, the amount of $1 Million, upon receipt of specified goods in Singapore'