| Abbreviation | Definition |
|---|---|
| USI | User System Interface |
| USLD | United States Long Distance |
| USOC | Universal Service Order Code |
| USPI | Universal Serial Phone Interface |
| UTFX | Unit Testing Framework - XSLT (Extensible Stylesheet Language Transformation) |
| UTI | Union Internationale des Telecommunications |
| UTL | Uganda Telecom Limited |
| UTL | Uganda Telecommunications Ltd |
| UTL | United Telecom Limited |
| UTL | United Telecoms Limited |
| UTP | Universal Transmission Protocol |
| UTP | Unshielded Twisted Pair |
| UTRA | Universal Terrestrial Radio Access |
| UTRAN | UMTS (Universal Mobile Telecommunication System) Terrestrial Radio Access Network |
| UVG | Universal Voice Grade |
| UWT | United World Telecom |
| UXW | UNE Exchange Wiring |
| VA | Voice Activity |
| VAC | Voice Activity Compression |
| VAD | Voice Activity Detector |