What are the consequences of a contract that is unenforceable?

Where the consequences of illegality are not specified by statute, courts have also developed a number of “exceptions” to the general common law rules that such contracts are unenforceable and that money or property exchanged in reliance on them cannot be recovered. Some of these exceptions are founded on the discretion of the court in relation to declaratory relief (see, e.g., Sidmay, supra, per Laskin, J.A. at p. 535 and Kelly, J.A. at p. 531) while others are founded on broader equitable considerations (see, e.g., Zimmerman v. Letkeman, 1977 CanLII 196 (SCC), [1978] 1 S.C.R. 1097).