A counter terrorism check is required for people who will have access to information, people, assets or environments which would be considered at risk from terrorist interests. A CTC check will involve a BPSS check, departmental or company records check, security questionnaire, criminal records check and Security Services check. The clearance will be valid for a set period of time before it has to be renewed and CTC usually requires you to be a resident of the UK for a minimum of 3 years.