A quasi contract is a legal obligation imposed by law to prevent unjust enrichment. This is also called a contract implied in law or a constructive contract. A quasi contract may be presumed by a court in the absence of a true contract, but not where a contract—either express or implied in fact—covering the same subject matter already exists.
Because a quasi contract is not a true contract, mutual assent is not necessary, and a court may impose an obligation without regard to the intent of the parties. When a party sues for damages under a quasi-contract, the remedy is typically restitution or recovery under a theory of quantum meruit. Liability is determined on a case-by-case basis.
The concept of a quasi contract in Bailey v. West, 249 A.2d 414. While recognizing the doctrine of quasi contract, the Court held that “the essential elements of a quasi-contract are a benefit conferred upon defendant by plaintiff, appreciation by defendant of such benefit, and acceptance and retention by defendant of such benefit under such circumstances that it would be inequitable to retain the benefit without payment of the value thereof”.
[Last updated in March of 2022 by the Wex Definitions Team]