November 4, 2025

Unjust Enrichment: The Weirdest Cause of Action You’ve Never Thought About

By Laura Trachtman

Have you ever stopped to think about unjust enrichment as a cause of action? It’s wild. It’s neither a breach of contract cause of action nor a tort, and it’s grounded in equity. The entire purpose of the cause of action is to prevent unfairness. 

What is unjust enrichment? The Court of Appeals in Columbia Mem’l Hosp. v. Hinds, 38 N.Y.3d 253, 275, 192 N.E.3d 1128, 1137 (2022) sets forth the following important notes on the cause of action (all internal citations and quotations removed):

  1. Unjust enrichment lies as a quasi-contract claim and contemplates an obligation imposed by equity to prevent injustice in the absence of an actual agreement between the parties 
  2. Unjust enrichment claims are rooted in the equitable principle that a person shall not be allowed to enrich [themselves] unjustly at the expense of another 
  3. The essential inquiry in any action for unjust enrichment … is whether it is against equity and good conscience to permit the defendant to retain what is sought to be recovered 
  4. To recover under a theory of unjust enrichment, a litigant must show that (1) the other party was enriched, (2) at that party’s expense, and (3) that it is against equity and good conscience to permit [the other party] to retain what is sought to be recovered 
  5. An unjust enrichment claim is undoubtedly equitable and depends upon broad considerations of equity and justice and, to determine if it is against equity to permit a party to retain what is sought to be recovered, courts look to see if a benefit has been conferred on the defendant under mistake of fact or law, if the benefit still remains with the defendant, if there has been otherwise a change of position by the defendant, and whether the defendant’s conduct was tortious or fraudulent

What is a quasi-contractual cause of action? It’s a cause of action where one party receives the benefit of another party’s efforts. It doesn’t require mutual assent, because it’s not an actual contractual cause of action. 

What’s equity, and what’s an equitable principle? Simply put, equity is about fairness.  In a case involving unjust enrichment, the important inquiry is whether it’s fair to allow the party which received the benefit to keep it. Put another way, the important inquiry is whether allowing the party to keep the benefit is unfair to the person conferring the benefit. 

There also must be a relationship between the party who was enriched and the party who did the enriching that could have caused reliance or inducement. While there needn’t be a fiduciary relationship, at least some special relationship needs to be in existence. 

Where does unjust enrichment fit in? That’s the big question. It doesn’t result from an oral agreement where one party stiffed another: that’s a contractual cause of action. It doesn’t result from one party stealing from another: that’s a tortious cause of action. It doesn’t result from one party giving something to another and then changing their mind, either. Instead, it exists in the narrow space between tort and contract where one party receives a benefit from another party and it simply would not be fair to allow the receiving party to keep the benefit. 

The pattern jury instructions are helpful in understanding this entire cuckoo bananas cause of action:  

While unjust enrichment is termed a quasi-contractual cause of action, it is not based on a contract or promise at all; it is an obligation that the law creates, in the absence of any agreement, when the acts of the parties or others have placed in the possession of one person money, or its equivalent, under such circumstances that in equity and good conscience he or she ought not to retain it. In such circumstances, equity merely intervenes to deem the parties in privity to each other, E.J. Brooks Company v Cambridge Security Seals, 31 NY3d 441, 80 NYS3d 162, 105 NE3d 301 (2018). The contract is a mere fiction, a form imposed in order to adapt the case to a given remedy; the law creates it, regardless of the intention of the parties, to assure a just and equitable result, E.J. Brooks Company v Cambridge Security Seals, supra; Clark-Fitzpatrick, Inc. v Long Island R. Co., 70 NY2d 382, 521 NYS2d 653, 516 NE2d 190 (1987); Core Development Group LLC v Spaho, 199 AD3d 447, 157 NYS3d 416 (1st Dept 2021) (unjust enrichment imposes obligation in equity to prevent injustice, in absence of actual agreement between parties).

So, why bother to plead unjust enrichment? It’s a good idea to plead unjust enrichment in situations where you’re not sure whether your contractual cause of action is going to bear out successfully, or you don’t have one. It also works well when you’re not sure about a tortious cause of action, like conversion, will succeed. I usually see it coupled with breach of fiduciary duty, which makes sense, as it would be inequitable to allow someone to retain a benefit gained which they haven’t earned. 

In sum, unjust enrichment is a tricky cause of action, but it’s one that I really like, because if all other causes of action fail, but if the Court thinks that it is unfair to allow the other side to retain the benefit at issue, it’s entirely possible that a client could receive restitution.