List of activities classified inside the UK SIC Code 61100
- Cable service
- Teletext and other electronic message and information services (wired telecommunications)
- Telephone service operation of 0898 numbers
- Telephone service (wired telecommunications)
- Telephone exchange
- Telephone communication (wired telecommunications)
- Telegraph communication
- Telegram service
- Teleconferencing services (wired telecommunications)
- Telecommunication network maintenance (wired telecommunications)
- Sound transmission via cables, broadcasting, relay or satellite
- Shared business telephone network services (wired telecommunications)
- Image transmission via cables, broadcasting, relay or satellite
- Hull telephone service
- Electronic mail services (wired telecommunications)
- Dedicated business telephone network services (wired telecommunications)
- Data transmission (via cables, broadcasting, relay or satellite)
- Data network management and support services (wired telecommunications)
- Telex service (wired telecommunications)