Q376: What is the difference between taxis and private hire vehicles?
Taxis are hackney carriages and are licensed to pick people up from the roadside, i.e. hailing a cab.
Private hire vehicles are only permitted to pick up pre arranged bookings and are not permitted to pick people up from the side of the road.
If you have a complaint about either type of vehicle and it does not involve a criminal complaint then contact your local authority. Each local authority will have a department that deals with such issues. It is advisable to get the badge number of the driver involved as well as the vehicle's licence plate number.
See the website in related information to find your local authority.