When does the parol evidence rule apply? What are the exceptions to this rule?
Where the parties have expressed their agreement wholly in writing, the ‘parol evidence rule’ will apply. The rule states that if the written document is intended by the parties to contain a complete record of their transaction, extrinsic evidence is not admissible to add to, or vary, or contradict it: Mercantile Bank of Sydney v Taylor (1891) 12 LR (NSW) 252. If the parol evidence rule is applied strictly, it could lead to injustice and hardship.
