Source : Free On-Line Dictionary of Computing

service provider
     
         An organisation that provides a service by
        telephone, such as an 0800 (toll free) number.  The service
        provider buys the services of a telecom supplier (e.g. BT) but
        advertises the service and deals with the calls itself.
        Increasingly, service providers are now also managing their
        advanced {call-routing}.
     
        (1996-08-27)