CSIS is the Civil Service Insurance Society, a not-for-profit organisation set up to provide insurance for people working in the public sector. They provide car, home, travel and life insurance.
CSIS offers insurance to current, former and retired workers of government-backed bodies, including the Armed Forces, Police, NHS and local government.
Employees of private companies formerly owned by the state may also qualify, organisations such as BT, Royal Mail and British Rail are among these.
Not everyone will be able to use the services provided by CSIS. If you're not sure whether you qualify, the organisation says it's best to call and find out.
Their headquarters are based in Kent, UK.