Pinnel’s rule is a legal principle that states that payment of a lesser sum than the full amount owed under a contract does not discharge the entire debt unless the creditor agrees to accept the lesser sum as full payment. This principle was established in the case of Pinnel’s Case in 1602 and has been applied in various forms in common law jurisdictions.
Promissory estoppel, on the other hand, is a principle that allows a party to enforce a promise even if there is no consideration or contract to support the promise. The doctrine of promissory estoppel arose as an exception to the rule that consideration is necessary to create a binding contract.
In essence, promissory estoppel allows a party who has relied on a promise made by another party to enforce that promise, even if there was no consideration exchanged between the parties. This doctrine is based on the principle that it would be unfair to allow a party to make a promise and then renege on that promise, especially if the other party has relied on that promise to their detriment.
In some cases, the principles of Pinnel’s rule and promissory estoppel may come into conflict. For example, if a creditor agrees to accept a lesser sum than the full amount owed under a contract, but the debtor has relied on that promise to their detriment, the principles of promissory estoppel may be invoked to enforce the promise, even if it would otherwise be contrary to the principles of Pinnel’s rule.
Overall, Pinnel’s rule and promissory estoppel are two legal principles that may be applied in different circumstances to determine the validity and enforceability of a promise or agreement.