| The Phonco, Inc. | Network Services Long Distance | Philadelphia, PA | Inactive |
| The St. Thomas & San Juan Telephone Co., Inc. | - | McLean, VA | Inactive |
| The St. Thomas & San Juan Telephone Co., Inc. | - | Herndon, VA | Active |
| The Trident Corporation, Inc. | - | Dania Beach, FL | Active |
| Tismi Wireless, LLC | - | - | Inactive |
| Titan Technologies, LLC | - | Marlboro, NJ | Active |
| Toledo Area Telecom. Services, Inc. | Buckeye Telesystem | Toledo, OH | Inactive |
| Toly Digital Network, Inc. | - | JUPITER, FL | Active |
| Tomorrow Valley Communications, LLC. | - | AMHERST, WI | Inactive |
| Tonatiu Services, LLC d/b/a Tonatiu Telecom | - | Cutler Bay, FL | Active |
| Topsham Communications, LLC. | - | Hammond, NY | Active |
| Total Access Telecom, Inc | - | Henderson, NV | Active |
| Total Communication Services, Inc. | - | Houston, TX | Active |
| Total Communications Systems, Inc. | - | Lennon, MI | Active |
| Total Communications, Inc. | Total Comm Long Distance | Curtis, NE | Inactive |
| Total Communications, Inc. | - | East Hartford, CT | Inactive |
| Total Holdings, Inc. | GTC Communications | Long Beach, CA | Active |
| Totel Customer Services, Inc. | - | Ochelata, OK | Active |
| Touch 1 Communications, Inc. | - | Dallas, TX | Inactive |
| Touch Asia Call Center, Inc. | - | Sacramento, CA | Inactive |
| Traceroad Communications, Inc. | - | Smithville, MS | Active |
| Tralee Telephone Company, LLC | - | Blue Bell, PA | Inactive |
| Trans Border Enterprises, LLC | - | Miami Beach, FL | Inactive |
| Trans National Communications International, Inc. | - | Boston, MA | Inactive |
| Trans National Communications, Inc. | - | Boston, MA | Active |
| TransNet Connect, Inc. | - | Duluth, GA | Inactive |
| TransWorld Telephone, LLC | - | Atlanta, GA | Inactive |
| Transamerica Telecom, Inc. | - | Indiana, PA | Active |
| Transcendence, Inc. | - | Montgomery, AL | Inactive |
| Transit Voice LLC | - | Roslyn Harbor, NY | Active |
| Transworld Network, Corp. | Transworld Network Corp | OLDSMAR, FL | Active |
| Tremcom International, Inc. | - | Los Alamitos, CA | Active |
| Tri Rural Independent Operations, Inc. | - | Viola, IL | Active |
| Tri-Com, LLC | Geneseo, Cambridge & Henry County Long Distance | Geneseo, IL | Active |
| Tri-County Telcom, Inc | - | Strum, WI | Active |
| Triangle Communication System, Inc. | In Touch Long Distance | Havre, MT | Active |
| Trinity Telecommunications, Inc. | Trinity Connect | New POrt Richey, FL | Active |
| Tuebor, Inc. | - | Kalamazoo, MI | Active |
| Tularosa Communications, Inc. | Tularosa Communications Inc | Tularosa, NM | Active |
| Twin City Capital, LLC | Small Business America, Inc. | Las Vegas, NV | Active |
| Twin Lakes Communications, Inc. | Twin Lakes Long Distance | Gainesboro, TN | Active |
| Twin Valley Communications, Inc. | - | Miltonvale, KS | Active |
| U S WEST Long Distance, Inc. | QWest Long Distance, Inc. | Denver, CO | Active |
| U.S. Connection, Inc. | - | McLean, VA | Inactive |
| U.S. South Communications, Inc. | US South & IWCOMM | Atlanta, GA | Active |
| U.S. Telecom Long Distance, Inc. | - | Las Vegas, NV | Active |
| UI Long Distance, Inc. | Fairpoint Communications, Inc. | Mattoon, IL | Active |
| ULTRA NETWORKS AND COMMUNICATIONS LLC | - | Springfield, VA | Active |
| UPM Marketing, Inc. | - | Hillsboro, OR | Active |
| US Telecom, Inc. | Sprint Services | Overland Park, KS | Active |