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 Texas, 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 principles of fairness and is designed to prevent injustice that would result if the promise were not enforced. The elements required to establish promissory estoppel in Texas include: (1) a clear and definite promise, (2) the promisor's expectation or foreseeability that the promisee will rely on the promise, (3) actual and reasonable reliance by the promisee on the promise to their detriment, and (4) the necessity of enforcing the promise to avoid an injustice. If these elements are met, Texas courts may compel the promisor to fulfill their promise or provide compensation for the losses incurred due to the reliance on the promise. This doctrine is particularly relevant in situations where a formal contract is unenforceable due to lack of consideration or other technical deficiencies, but where one party has relied on the other's promise to their detriment.