A contract is an agreement that specifies certain legally enforceable rights and obligations pertaining to two or more parties. A contract typically involves consent to transfer of goods, services, money, or promise to transfer any of those at a future date. 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.
Contract law, the field of the law of obligations concerned with contracts, is based on the principle that agreements must be honoured.Hans Wehberg, Pacta Sunt Servanda, The American Journal of International Law, Vol. 53, No. 4 (Oct., 1959), p.775.; Trans-Lex.org Principle of Sanctity of contracts Like other areas of private law, contract law varies between jurisdictions. In general, contract law is exercised and governed either under common law jurisdictions, civil law jurisdictions, or mixed-law jurisdictions that combine elements of both common and civil law. Common law jurisdictions typically require contracts to include consideration in order to be valid, whereas civil and most mixed-law jurisdictions solely require a meeting of the minds between the parties.
Within the overarching category of civil law jurisdictions, there are several distinct varieties of contract law with their own distinct criteria: the German tradition is characterised by the unique doctrine of abstraction, systems based on the Napoleonic Code are characterised by their systematic distinction between different types of contracts, and Roman-Dutch law is largely based on the writings of renaissance-era Dutch jurists and case law applying general principles of Roman law prior to the Netherlands' adoption of the Napoleonic Code. The UNIDROIT Principles of International Commercial Contracts, published in 2016, aim to provide a general harmonised framework for international contracts, independent of the divergences between national laws, as well as a statement of common contractual principles for arbitrators and judges to apply where national laws are lacking. Notably, the Principles reject the doctrine of consideration, arguing that elimination of the doctrine "bring[s] about greater certainty and reduce litigation" in international trade.UNIDROIT Principles of International Commercial Contracts The Principles also rejected the abstraction principle on the grounds that it and similar doctrines are "not easily compatible with modern business perceptions and practice".
Contract law can be contrasted with tort law (also referred to in some jurisdictions as the law of delicts), the other major area of the law of obligations. While tort law generally deals with private duties and obligations that exist by operation of law, and provide remedies for civil wrongs committed between individuals not in a pre-existing legal relationship, contract law provides for the creation and enforcement of duties and obligations through a prior agreement between parties. The emergence of quasi-contracts, quasi-torts, and quasi-delicts renders the boundary between tort and contract law somewhat uncertain.Beatson, Anson's Law of Contract (1998) 27th ed. OUP, p.21
Overview A contract is a set of constructs created by distinct parties (Meeting of the minds) working to accomplish more than they could alone. Contracts are generally written and signed, and the legal enforceability of them secures some shelter of reliability. Contracts are widely used in commercial law, and for the most part form the legal foundation for transactions across the world. Common examples include contracts for the sale of services and goods, construction contracts, contracts of carriage, software licenses, employment contracts, insurance policies, sales or leases of land, among others. A contractual term is a "provision forming part of a contract".Martin, E. [ed] and Law, J. [ed], Oxford Dictionary of Law, ed6 (2006, London:OUP). Each term gives rise to a contractual obligation, breach of which can give rise to litigation, although a contract may also state circumstances in which performance of an obligation may be excused. Not all terms are stated expressly, and terms carry different legal weight depending on how central they are to the objectives of the contract.
Contract duration may cover any period of time agreed by the parties. There are advantages to long term contracting, which fosters the development of trust, innovation, and better commercial relationships, but short term contracting also provides for flexibility and the ability to respond more readily to changing market conditions.McQueen, N., "Can you secure supplies without getting trapped in contracts?" in Supply Management, April-June 2023, page 58 A "term contract", also known as a "measured term contract",Boardman, A., Measured Term Contract 2026: Early Market Engagement for City of London Works Framework, Thornton and Lowe, published on 12 March 2026, accessed on 14 September 2026 provides for the delivery of goods or services over a defined period of time.NEC, Term Service Contract, accessed on 14 September 2026
Contracting is a specific phase within procurement. It includes creating, negotiating, and managing contracts.
Obligations created by contracts can generally be transferred, subject to requirements imposed by law. Laws regarding the modification of contracts or the assignment of rights under a contract are broadly similar across jurisdictions.For the assignment of claim see Trans-Lex.org In most jurisdictions, a contract may be modified by a subsequent contract or agreement between the parties to modify the terms governing their obligations to each other. This is reflected in Article 3.1.2 of the Principles of International Commercial Contracts, which states that "a contract is concluded, modified or terminated by the mere agreement of the parties, without any further requirement". Assignments are typically subject to statutory restrictions, particularly with regard to the consent of the other party to the contract.
Contract theory is a large body of legal theory that addresses normative and conceptual questions in contract law. One of the most important questions asked in contract theory is why contracts are enforced. One prominent answer to this question focuses on the economic benefits of enforcing bargains. Another approach, associated with Charles Fried in his book Contract as Promise, maintains that the general purpose of contract law is to enforce promises. Other approaches to contract theory are found in the writings of legal realists and critical legal studies theorists, which have propounded Marxist and feminist interpretations of contract. Attempts at understanding the overarching purpose and nature of contracting as a phenomenon have been made, notably relational contract theory. Additionally, certain academic schools of thought, such as 'law and economics', focus on questions of transaction cost and 'efficient breach' theory.
Another important dimension of the theoretical debate in contract is its place within, and relationship to a wider law of obligations. Obligations have traditionally been divided into contracts, which are voluntarily undertaken and owed to a specific person or persons, and obligations in tort which are based on the wrongful infliction of harm to certain protected interests, primarily imposed by the law, and typically owed to a wider class of persons. Research in business and management has also paid attention to the influence of contracts on relationship development and performance.
Private international law is rooted in the principle that every jurisdiction has its own distinct contract law shaped by differences in public policy, judicial tradition, and the practices of local businesses. Consequently, while all systems of contract law serve the same overarching purpose of enabling the creation of legally enforceable obligations, they may contain significant differences. Accordingly, many contracts contain a choice of law clause and a forum selection clause to determine the jurisdiction whose system of contract law will govern the contract and the court or other forum in which disputes will be resolved, respectively. Failing express agreement on such matters in the contract itself, countries have rules to determine the law governing the contract and the jurisdiction for disputes. For example, European Union Member States apply Article 4 of the Rome I Regulation to decide the law governing the contract, and the Brussels I Regulation to decide jurisdiction.
History
Contracts have existed since antiquity, forming the basis of trade since the dawn of commerce and sedentism during the Neolithic Revolution. A notable early modern development in contract law was the emergence of the hawala system in the Indian subcontinent and the Arab world, under which a series of contractual relationships formed the basis of an informal value transfer system spanning the Silk Road. In the Indian subcontinent, the hawala system gave rise to the hundi, a transferrable contract entitling its holder in due course to obtain money from its issuer or an agent thereof, giving rise to the principle underlying contemporary negotiable instruments.
The hawala system also influenced the development of agency in common law and in civil laws. In Roman law, agents could not act on behalf of other individuals in the formation of binding contracts. On the other hand, Islamic law accepted agency as permissible in not only contract law but in the law of obligations generally, an approach that has since become mainstream in common law, mixed law, and most civil law jurisdictions. Analogously, the transfer of debt, which was not accepted under Roman law, became widely practiced in medieval European commerce, owing largely to trade with the Muslim world during the Middle Ages.
Since the nineteenth century, two distinct traditions of contract law emerged. Jurisdictions that were previously British colonies generally adopted English common law. Other jurisdictions largely adopted the civil law tradition, either inheriting a civil law legal system at independence or adopting civil and commercial codes based on German or French law. While jurisdictions such as Japan, South Korea, and the Republic of China modelled their contract law after the German pandectist tradition, the Arab world largely modelled its legal framework after the Napoleonic Code. While the Netherlands adopted a legal system based on the Napoleonic Code in the early 19th century, Dutch colonies retained the precedent-based Roman-Dutch law. British colonies in Southern Africa adopted Roman-Dutch principles in areas of private law via reception statutes adopting South African law, retaining Roman-Dutch law for most matters of private law while applying English common law principles in most matters of public law. Saint Lucia, Mauritius, Seychelles, and the Canadian province of Quebec are mixed-law jurisdictions which primarily adhere to French legal tradition with regard to contract law and other principles of private law.