You would flag an employee as a director when that person is officially a company director.
The reason is mainly for payroll processing:
Director status is used in payroll calculations, especially for things like National Insurance contributions.
This setting does not come from HR data, so it needs to be recorded separately in payroll.
Because of that, the change is usually handled by your payroll agent or payroll system, not directly in HR.â
For more information about this topic, you can check the official government information.