There is increasing support in Europe for individual criminal penalties for cartel activity. The UK’s initial experience of criminalisation has not been successful and reform has been suggested. It is argued that when designing a criminal cartel offence deterrence cannot be the only concern and the true wrongdoing in cartel behaviour must be at it centre. Cartel harm does not provide good basis for criminalisation and it is argued that its proper basis should be the individual cartelist’s intention to subvert the competitive process. A reformed UK cartel offence, without the current dishonesty test, should reflect the central concern of subverting the competitive process clearly.