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 Florida, the doctrine of unjust enrichment is recognized and applied by the courts when one party has received a benefit unjustly at the expense of another, and there is no valid contract governing the transaction between the parties. The doctrine operates on the principle that it is unfair for one party to retain a benefit without paying for it when there is no legal justification for the retention. To establish a claim for unjust enrichment in Florida, a plaintiff must demonstrate that (1) the plaintiff has conferred a benefit on the defendant, (2) the defendant has knowledge of the benefit, (3) the defendant has accepted or retained the benefit under circumstances that make it inequitable for them to retain it without paying the value thereof. The remedy for unjust enrichment is typically restitution, where the defendant may be required to return the benefit or pay for its value. This doctrine is equitable in nature, meaning it is based on principles of fairness and justice rather than strict legal rules. It is important to note that if a valid, enforceable contract exists, the doctrine of unjust enrichment does not apply, as the contract itself dictates the parties' rights and remedies.