Walker v Sell

The case of *Walker v Sell* concerned a dispute between the appellant, Mr. Walker, and the respondent, Mr. Sell, regarding the enforceability of a deed of settlement. The matter came before the High Court of Australia.

The central legal issue before the High Court was whether the deed of settlement, which contained a release of all claims, was vitiated by a fundamental mistake as to the existence of a cause of action that was the subject of the settlement. Specifically, the court had to determine if the mistake was so fundamental as to render the deed void *ab initio* or merely voidable.

The High Court held that a mistake as to the existence of a cause of action, even if fundamental, does not render a deed of settlement void *ab initio*. Instead, such a mistake may render the deed voidable, meaning it remains valid and binding unless and until it is set aside by a court. The court reasoned that the parties to a settlement deed are presumed to intend to compromise all existing disputes, and a mistake about the strength or existence of a claim does not negate this intention. The principles of contract law, particularly concerning mistake, were applied, distinguishing between mistakes that prevent the formation of a contract and those that affect its enforceability.

The High Court dismissed the appeal, upholding the enforceability of the deed of settlement.