of Pinnel’ case is the payment of a lesser sum will not extinguish a debt for a greater amount. The rule of pinnel’s case was unfair because the payment of a lesser sum not sufficient to discharge a whole debt, creditor’s promise not to sue the debtor for further payment not enforceable by law (Foakes V Beer) and creditor can still sue for any outstanding sum form a debtor This rule enables a creditor to make a promise and then change his mind. The case Foakes v Beer Foakes owed Beer a