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 court to enforce a promise even when a formal contract does not exist or when certain elements of a contract are missing. The doctrine is based on the principles of equity and fairness, aiming to prevent injustice that would result from not enforcing the promise. The elements required to establish promissory estoppel in Pennsylvania are: (1) the existence of a promise that is clear and definite; (2) the promisor must have reasonably expected the promisee to rely on the promise; (3) the promisee must have actually relied on the promise in a substantial and reasonable way; and (4) the reliance must have resulted in a detriment to the promisee. If these elements are met, Pennsylvania courts may enforce the promise to the extent necessary to remedy the harm caused by the reliance. This doctrine is particularly important in situations where formal contract requirements are not satisfied, but where parties have acted in reliance on promises made.