Change of position is a defence to a claim in

unjust enrichment In laws of equity, unjust enrichment occurs when one person is enriched at the expense of another in circumstances that the law sees as unjust. Where an individual is unjustly enriched, the law imposes an obligation upon the recipient to make re ...

which operates to reduce a defendant's liability to the extent to which his or her circumstances have changed as a consequence of an enrichment.

History

The historical core of the law of unjust enrichment consists of the

quasi-contract A quasi-contract (or implied-in-law contract or constructive contract) is a fictional contract recognised by a court. The notion of a quasi-contract can be traced to Roman law and is still a concept used in some modern legal systems. Quasi Contrac ...

ual actions of

money had and received An action for money had and received to the plaintiff's use is the name for a common law claim derived from the form of action known as ''indebitatus assumpsit''. The action enabled one person to recover money which has been received by another: fo ...

, money paid to the defendant's use,

quantum meruit ''Quantum meruit'' is a Latin phrase meaning "what one has earned". In the context of contract law, it means something along the lines of "reasonable value of services". In the United States, the elements of ''quantum meruit'' are determined by ...

and quantum valebat. These personal

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 ...

actions generated an obligation on the part of the defendant to give

restitution The law of restitution is the law of gains-based recovery, in which a court orders the defendant to ''give up'' their gains to the claimant. It should be contrasted with the law of compensation, the law of loss-based recovery, in which a court ...

of a gain acquired at the expense of the plaintiff. This liability was strict and independent of any wrongdoing on the part of the recipient. Change of position provides a defence to a defendant where it would be inequitable to compel him or her to make restitution. The defence was recognised as part of the English law of unjust enrichment by Lord Goff in ''

Lipkin Gorman v Karpnale Ltd is a foundational English unjust enrichment case. The House of Lords unanimously established that the basis of an action for money had and received is the principle of unjust enrichment, and that an award of restitution is subject to a defence ...

'' 9912 AC 548.

Cases & Materials

*'' Ministry of Health v Simpson''

951 Year 951 ( CMLI) was a common year starting on Wednesday (link will display the full calendar) of the Julian calendar. Events By place Europe * King Berengar II of Italy seizes Liguria, with help from the feudal lord Oberto I. He re ...

AC 251, affirming ''

Re Diplock ''Re Diplock'' or ''Ministry of Health v Simpson'' 951AC 251 is an English trusts law and unjust enrichment case, concerning tracing and an action for money had and received. Facts Various charities, including the Royal Sailors Orphans Girls� ...

948 Year 948 ( CMXLVIII) was a leap year starting on Saturday (link will display the full calendar) of the Julian calendar. Events By place Byzantine Empire * Arab–Byzantine War: Hamdanid forces under Sayf al-Dawla raid into Asia Minor ...

Ch 465 *''

'' 9912 AC 548 *

Charles Mitchell Charles Mitchell may refer to: * Charles Mitchell (footballer), British soccer player * Charles Mitchell (academic) (born 1965), professor of law at University College, London * Charles Mitchell (American football) (born 1989), American football ...

, 'Change of Position: the developing law'

005 ''005'' is a 1981 arcade game by Sega. They advertised it as the first of their RasterScan Convert-a-Game series, designed so that it could be changed into another game in minutes "at a substantial savings". It is one of the first examples of a ...

''LMCLQ'' 168 * Graham Virgo, ''Principles of the Law of Restitution'' (3rd ed, 2015) *

Andrew Burrows Andrew Stephen Burrows, Lord Burrows, (born 17 April 1957BURROWS, Prof. Andrew ...

, ''The Law of Restitution'' (3rd ed, 2011) *Andrew Burrows, James Edelman and Ewan McKendrick, ''Cases and Materials on the Law of Restitution'' (2nd ed, 2007) at 762-804 Unjust enrichment Restitution {{law-term-stub