Promissory estoppel is an equitable theory of recovery that permits enforcement of a promise when one or more elements necessary to create an enforceable contract are missing. The elements of promissory estoppel are generally: (1) a promise; (2) foreseeability of reliance by the promisor; (3) substantial and reasonable reliance by the promisee to its detriment; and (4) enforcing the promise is necessary to avoid injustice.
In Pennsylvania, promissory estoppel serves as a legal remedy that allows a party to enforce a promise even when a formal contract does not exist or certain elements for a contract are lacking. The doctrine is based on the principle of fairness and seeks to prevent injustice that would result if the promise were not enforced. The elements required for promissory estoppel in Pennsylvania are: (1) the promisor makes a promise that he or she should reasonably expect to induce action or forbearance on the part of the promisee, (2) the promisee actually takes action or refrains from taking action in reliance on the promise, (3) the reliance is substantial and results in a detriment to the promisee, and (4) enforcement of the promise is necessary to avoid injustice. Pennsylvania courts will consider these elements when determining whether to apply promissory estoppel in a given case.