| Abbreviation | Definition |
|---|---|
| TD | Teledyne |
| TE | Technipower |
| TF | Transformer Design |
| TG | Triange |
| TH | Theim |
| TH | Thiokol |
| TIP | Telephone Industries of Pakistan |
| TN | Technitrol |
| TR | Tracor |
| TT | Transitron |
| TW | TRW (supplier) |
| TW | TRW (Thompson Ramo Wooldridge) |
| TY | Taiyo Yuden |
| UC | Union Carbide |
| UHBVN | Uttar Haryana Bijli Vitran Nigam |
| UKPRN | UK Provider Reference Number |
| UL | Ultronix |
| UN | Dun & Bradstreet |
| UN | Univac |
| UR | Unitrode |