• A contract validity entered into may be rendered unenforceable by:
o Illegality: if for any reason the contract becomes illegal, it is unenforceable.
o Duress: if evidence suggests that the contract was procured by actual violence or threats thereof.
o Undue influence: if it is proved that one of the parties did not make an independent decision on the contract.
o Mistake: if the contract is vitiated by an operative mistake for example common,mutual or unilateral
o Frustration: where further performance of the obligations become impossible by reason of extraneous circumstances for which neither party is to blame.