People with Significant Control
All UK limited companies must have at least one director, one shareholder and one person with significant control (PSC). All these roles can be taken by one person, however - as well being able to appoint other people, you can also appoint other companies in roles too.
Since April 2016 all UK limited companies and limited liability partnerships should be keeping a Register of People with Significant Control (PSC) in the company. This information should then be included in the Confirmation Statement - which has now replaced the Annual Return.