service provider

from The Free On-line Dictionary of Computing (8 July 2008)

service provider

   <communications> 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)