It depends on a number of factors, such as the seriousness of the illegality and how illegality relates to the main purpose of the treaty. The types of illegality may overlap. Among the consequences of illegality are the possibilities: the illegality of a contract depends on (1) the right of the contracting country and (2) on the right of the place of execution. The rules vary according to the law of each country. The consequences of an illegal contract can be severe. As soon as a contract is considered illegal and invalid, the court will refuse the application of the contract and leave the parties as it is. In conclusion, it is generally accepted that illegality renders a contract null or void. However, Parkingeye`s decision showed a characterization for this rule, according to which if the intent was limited to a type of partial and minor benefit and that could be changed at any time, the contract could be maintained independently of that. The application of this principle depends on the proof of intent.
The chosen performance method and the degree of participation in this illegal service may be in such a way as to transform the contract into an illegal contract. Therefore, the court will consider each case on its facts. Whether a contractual case is unlawfully tainted is decided by applying a number of factors against the turn of events that triggered the litigation and applies to the assessment of the seriousness of the illegality. A contract that does not necessarily have to be executed illegally, but which is ultimately executed illegally by one of the parties, is considered somewhat different from that which is illegal in education. In these circumstances, the party who committed the illegal act is deprived of all rights, but the corresponding remedies will remain available to an innocent party who was not aware of the illegality. However, if the innocent part of the illegality, which it cannot impose or rely on the treaty, has fallen or participated in Serdiel. Whether illegality is sufficient to trigger legal consequences of illegality depends on the facts of the case: that is, what happened and the law that made the treaty illegal. In Colen v Cebrian , a couple claimed commissions due before they were fired from the company they were working for. The husband had avoided tax by giving his wife a commission to which he was entitled by contract. The company stated that they should not pay the commission because the contract was tainted by illegality and the labour tribunal decided that they did not have to pay the commission. However, the Court of Appeal set aside the Tribunal`s decision and held that a clear distinction was drawn between the Commission`s method of calculation and its final destination.