The doctrine of unjust enrichment applies the principles of restitution to disputes that are not governed by a contract between the parties. It characterizes the result of a failure to make restitution under circumstances that give rise to an implied or quasi-contractual obligation to return those benefits.

The courts describe this claim in general principles. For example, courts have stated that a claim for unjust enrichment seeks to restore money where equity and good conscience require restitution; it is not premised on wrongdoing, but seeks to determine to which party, in equity, justice, and law, the money belongs; and it seeks to prevent unconscionable loss to the payor and unjust enrichment to the payee.

Because recovery based on unjust enrichment of another party relies on the court's sense of fairness or equity rather than the law, it is often referred to as the equitable doctrine of unjust enrichment.

In Oklahoma, the doctrine of unjust enrichment is recognized and applied by courts when one party has received a benefit unjustly at the expense of another, and there is no valid contract governing the situation. This doctrine is rooted in principles of equity, aiming to prevent one party from being unjustly enriched at the expense of another. Oklahoma courts will consider an unjust enrichment claim to determine whether, under the circumstances, it would be inequitable for the party who received the benefit to retain it without providing compensation. The claim is not based on the existence of wrongdoing but on the notion that it is unjust for an individual to retain benefits without paying for them when fairness dictates otherwise. The remedy typically involves restitution, where the party who has been unjustly enriched must pay back the value of the benefit received. This equitable remedy ensures that the party who provided the benefit is made whole, and the party who received the benefit does not profit at the other's expense.