In common law countries such as the UK, Australia and New Zealand, passing off is a common law tort which can be used to enforce unregistered trade mark rights. The tort of passing off protects the goodwill of a trader from misrepresentation. In common law countries such as the UK, Australia and New Zealand, passing off is a common law tort which can be used to enforce unregistered trade mark rights. The tort of passing off protects the goodwill of a trader from misrepresentation.