A negotiable instrument is a document guaranteeing the payment of a specific amount of money, either on demand, or at a set time, whose payer is usually named on the document. More specifically, it is a document contemplated by or consisting of a contract, which promises the payment of money without condition, which may be paid either on demand or at a future date. The term has different meanings depending on its use in the application of different laws and depending on countries and contexts. The word "negotiable" refers to transferable and "instrument" refers to a document giving legal effect by the virtue of the law.

A contract is an agreement that specifies certain legally enforceable rights and obligations pertaining to two or more parties. A contract typically involves the transfer of goods, services, money, or a promise to transfer any of those at a future date, and the activities and intentions of the parties entering into a contract may be referred to as contracting. In the event of a breach of contract, the injured party may seek judicial remedies such as damages or equitable remedies such as specific performance or rescission. A binding agreement between actors in international law is known as a treaty.