Does an entire agreement clause prevent me from relying on pre-contract promises in Ontario?

An entire agreement clause states that the written contract represents the complete agreement between the parties and that no prior representations, promises, or negotiations outside the document form part of the deal. Ontario courts generally enforce these clauses, making it difficult to add terms from pre-contract discussions to what the contract requires.

The parol evidence rule works alongside this — courts are reluctant to admit external evidence to contradict or vary the clear written terms of a completed contract.

However, entire agreement clauses do not provide absolute protection. They typically cannot shield a party from liability for fraudulent misrepresentation that induced the other party to sign. Depending on their language, they may also not cover negligent misrepresentation. Ontario courts scrutinize the exact wording carefully: a clause that excludes representations does not necessarily exclude collateral warranties, and vice versa.

From a practical standpoint, if you were promised something specific before signing, and you are now relying on that promise in a dispute, an entire agreement clause may be a significant obstacle. The more important the pre-contract promise was to your decision to sign, the more important it is to have it written into the contract itself.