"End-user services" may mean services that are final in the sense that they are provided to end-users and not re-sold.

There is too little context in the question, so below are two other options.
(1)
IT:
"terminal services provider"
http://en.wikipedia.org/wiki/Terminal_Services
http://technet.microsoft.com/en-us/library/cc740011(WS.10).a...
(2)
Telecommunications (often in international calls and VoIP):
"call termination provider", "call termination services provider"