A quasi-contract (or implied-in-law contract or constructive contract) is a fictional
contract A contract is a legally enforceable agreement between two or more parties that creates, defines, and governs mutual rights and obligations between them. A contract typically involves the transfer of goods, services, money, or a promise to ...
recognised by a court. The notion of a quasi-contract can be traced to
Roman law Roman law is the law, legal system of ancient Rome, including the legal developments spanning over a thousand years of jurisprudence, from the Twelve Tables (c. 449 BC), to the ''Corpus Juris Civilis'' (AD 529) ordered by Eastern Roman emperor J ...
and is still a concept used in some modern legal systems. Quasi Contract laws have been deduced from the Latin statement "Nemo debet locupletari ex aliena jactura", which proclaims that no man should grow rich out of another person's loss. It was one of the central doctrines of Roman law.


common law In law, common law (also known as judicial precedent, judge-made law, or case law) is the body of law created by judges and similar quasi-judicial tribunals by virtue of being stated in written opinions."The common law is not a brooding omnipres ...
jurisdictions, the law of quasi-contract can be traced to the medieval form of action known as ''indebitatus assumpsit''. In essence, the plaintiff would recover a money sum from the defendant ''as if'' the defendant had promised to pay it: that is, ''as if'' there were a contract subsisting between the parties. The defendant's promise—their agreement to be bound by the "contract"—was implied by law. The law of quasi-contract was generally used to enforce restitutionary obligations. The form of action known as ''indebitatus assumpsit'' came to include various sub-forms known as the common money counts. The most important of these for the later development of the law of quasi-contract included: (i) actions for money had and received to the plaintiff's use; (ii) actions for money paid to the defendant's use; (iii) '' quantum meruit''; and (iv) ''quantum valebant''. Quasi-contractual actions were generally (but not exclusively) used to remedy what would now be called unjust enrichment. In most common law jurisdictions the law of quasi-contract has been superseded by the law of unjust enrichment.See generally, Mitchell et al, '' Goff & Jones Law of Unjust Enrichment'' (8th ed, 2011); Carter et al, ''Mason & Carter's Restitution Law in Australia'' (2nd ed, 2008); Graham Virgo, ''The Principles of the Law of Restitution'' (3rd ed, 2015)

Quasi-contract and contract

A quasi-contract is distinct from a contract implied in fact and may be distinguished from an explicitly agreed contract. * ''Contract implied in fact.'' A person's assent to be bound by an agreement can be expressed or implied. In the latter case, assuming the requisite formalities for a valid contract are met, there is a perfectly normal contract. The only distinction between a contract arising by express agreement between two people and a contract implied-in-fact is that the latter was recognized by a court drawing inferences from facts proved at trial. When the plaintiff sued on either sort of contract, he was suing in the law of contract in respect of a consensually assumed obligation and her remedy for the defendant's breach was damages. * ''Quasi-contract''. In contrast, quasi-contract refers to situations in which a defendant is bound ''as if'' there were a contract. When the plaintiff sued on such a 'contract' by bringing an action of ''indebitatus assumpsit'', he was not enforcing some consensually assumed obligation, but rather an obligation imposed by law.

See also

* Implied-in-fact contract * Negotiorum gestio * Promissory estoppel * Restitution ** Unjust enrichment ** Officious intermeddler



Further reading

* ''The Law of Quasi-Contract'' by S. J. Stoljar; Sydney : Law Book Co. of Australasia, 1964 {{Authority control Contract law Law of obligations Legal fictions