166 ausgewählt
- Nicht ausgefüllt
- C.P.I.
- C.S.I.
- C.T.D.
- C3
- C3 - Calling Card Company
- Cable & Wireless
- Cable & Wireless BarTel
- Cable&wireless
- Cabo Verde Telecom
- Calble&wireless
- California Alliance Telecom
- Call Africa
- Call Europe
- Call Home
- Calling Card International
- Callmate Telecom
- CallPlus
- Callpoint
- CallTrak
- Camtel
- Canada Phone Card
- Canada Telecom Network, Inc.
- Canon
- Card Phone Australia
- CardCall International
- Cardcaller Canada
- Cardlink
- CardLink Services
- Cash Call
- Cat Telecom Public Company Limited
- Cat.Card
- CB
- CCT
- CDT, L.L.C.
- Cegetel
- Celcom
- Cellcard
- Cellcom
- Cellis
- Cellnet
- Cellplus
- Celltel
- Cellular one
- Cellway
- Celtel
- Centennial
- Centertel
- Central Telecom
- Ceský Telecom
- Cetelem
- Chawaleks
- Cheetah
- Chelyabinskvyazinform
- Chembell
- Chilli
- Chilli Arabien
- China Mobile
- China Netcom
- China Railcom
- China Satcom
- China Telecom
- China Telecom Corporation
- China Tietong
- China Unicom
- Chinese Industry Co.
- Chipknip
- Chippie
- Chitel
- Chithy
- Chunghwa Telecom
- CI-Telcom
- Cii Honeywell Bull
- CIP
- Cirte Manifatturiera
- Citadel
- CitiFon
- City Card
- Citycall
- Claro
- Classic
- Clear Communications
- Clifton
- Clifton Digital
- Clifton Telecard Alliance
- CML, Inc.
- CMOS Communications
- CMPT
- CMV Bank
- CNC
- CNC Communications Network
- Coast to Coast +
- Coast to Coast Communications, Inc.
- Coastcall
- Coinstar
- Collector's Communications
- Colli telecomunicazioni
- Combo
- Comcard Pacific
- Comco SA
- Come Phone
- Comfour
- Comfour Telecom BV
- Cominex
- Comité des PTT et de l'informatique
- Comms
- Communi Card
- Communicard
- Communications
- Communications Design Group Inc.
- Communitel
- Companhia Santomese de Telecomunicações
- Compañía Anónima Nacional de Teléfonos de Venezuela
- Compaq
- Compass Communications
- Comsat
- Comstar
- Comstar Moskau
- ComTel Debit Technologies, L.C.
- Comunitel
- Comviq
- Concorde
- Condor
- Conetco
- Conexus, Ltd.
- Connect
- Connect 'n Save
- Connex
- Conseil
- Contact Telecom
- Continental Telecom
- Converxis
- Copytex
- Cosmo
- Cosmophone
- Cosmote
- Costtel
- Côte d'Ivoire Telecom
- Cotel
- Covadis
- Crabeth College
- Creacomm
- Credifone
- CrossFone
- Crouzet
- CRT
- Crystal
- CSAT
- Csloxinfo
- CTACard
- CTBC Telecom
- CTC - Compañía De Teléfonos De Chile
- CTI
- CTI Móvil
- CTM
- CTMR
- CTN
- CTS Telecom, Inc.
- CTT Cabo Verde
- CTT Telecomunicações
- Cubacel
- Curacao Telecom
- Cute
- Cyberlight
- CyberTron
- Cyprus Telecommunications Authority
- Cyta