T
- Tele-Image
- Tampa International Airport
- Texas A&M University
- Texas Capital Bancshares, Inc.
- Texas Commerce Bancshares
- Texas Eastern Corporation
- Texas Tech University
- Trammel Crow Company
- Transwestern Pipeline Company
- Tulsa University
- TXU
U-Z
- U.S. Air Force
- US Airways
- U.S. Naval Facilities
- U.S. Engineering Command
- U.S. Postal Service
- University of Houston
- University of Texas Health Science Center
- University of Texas System
- Verio
- Visiting Nurse Association
- Wilcox Realty Group
- Wiltel Communications
- Winstar Communications