| CoID | Company | Type | Status | States Served | 24X7 Phone |
|---|---|---|---|---|---|
| TXACQ | TX11 Acquisition LLC dba Cellular One - CANCELLED | Wireless/Cellular/PCS | C | TX | 936-590-1568 |
| TXCOM | Advanced VoIP Solutions | PBX/PS911/Shared Tenant VoIP Provider | A | TX | 325-669-5899 |
| TXKCO | Texarkana College - CANCELLED | PBX/PS911/Shared Tenant | C | TX | 903-798-3330 |
| TXNET | Texas Network Communication, Inc. (Cancelled) | Facility | C | TX | 877-572-1030 |
| TXUL | TXU Communications Telephone Company (Cancelled - See CCITX) | Facility | C | TX | 888-608-7822 |
| TXUTS | TXU Communications Telecom Services (Cancelled - see CCITX) | Facility | C | TX | 888-608-7822 |
| TYCHR | Tychron Corporation | VoIP Provider | A | FL | 302-842-8751 |
| TYCOE | TYCO Electronics(Cancelled) | PBX/PS911/Shared Tenant | C | PA | 717-810-2255 |
| TYQ | Telergy Central (Cancelled) | Facility | C | US | 800-889-6716 |
| TZ0 | Tierzero | VoIP Provider | A | USA - Nationwide | 213-784-1397 |
| UAL | United Airlines | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | A | USA - Nationwide | 847-700-5800 |
| UAZ | University of Arizona - CANCELLED | PBX/PS911/Shared Tenant | C | AZ | 520-621-7999 |
| UBALT | University of Baltimore | PBX/PS911/Shared Tenant | A | MD | 800-773-7911 |
| UBC | The Community Agency (TCA) | Facility | A | IA | 712-930-5593 |
| UBN | UBNETWORKS (Cancelled) | Facility | C | CA | 213-489-9663 |
| UBNI | Unity Business Networks - CANCELLED | CLEC Facility | CLEC Reseller | VoIP | C | CO | 800-213-1236 |
| UBNX | Unity Business Networks - CANCELLED | CLEC Faciliy | CLEC Reseller | VoIP | C | CO | MN | OR | 800-231-1236 |
| UBTAL | Strata Networks | Co-Op/Rural | A | UT | 435-622-5007 |
| UBUFF | University at Buffalo | PBX/PS911/Shared Tenant | A | NY | 800-773-7911 |
| UCA | United Communications Association Inc. | CLEC Facility | A | KS | 620-855-9551 |
| UCAYD | Nevada Bell/Eschelon Telecom of NV (Cancelled) | UNE-Comp | C | NV | 800-275-0014 |
| UCB | UCB Inc - CANCELLED | PBX/PS911/Shared Tenant VoIP Provider | C | GA | 770-970-8770 |
| UCC | Union County College - CANCELLED | PBX | C | NJ | 908-709-0268 |
| UCDVN | Pacific Bell/Advanced TelCom Group (Cancelled) | UNE-Comp | C | CA, NV | 800-275-0014 |
| UCENC | Pacific Bell/Ernest Communications (Cancelled) | UNE-Comp | C | CA | 800-275-0014 |
| UCI | University of California Irvine - CANCELLED | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) Database Mgt System Provider | C | CA | 949-824-5222 |
| UCIME | Unity College | PBX/PS911/Shared Tenant | A | USA - Nation Wide | 207-509-7232 |
| UCINC | Universal Connectivity | VoIP Reseller VoIP Provider | A | AZ | CT | FL | MA | RI | TX | VT | VA | 860-808-1412 |
| UCLA | University of California - Los Angeles (CANCELLED) | CLEC Facility, Wireless/Cellular/PCS | C | CA | 310-206-0000 |
| UCNJ | County of Union NJ | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | A | NJ | 908-654-9800 |
| UCNVG | Pacific Bell / Navigator UNE Complex (Cancelled) | UNE-Comp | C | CA, NV | 800-275-0014 |
| UCPNJ | Pacific Bell/Pacific Centrex Services (Cancelled) | UNE | C | CA | 800-275-0014 |
| UCPS | Union County Public School | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) PBX/PS911/Shared Tenant Other - (must identify below) | PS/ALI from Frontier | A | NC | 704-296-3160 |
| UCR | University of California Riverside | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) PBX/PS911/Shared Tenant | A | CA | 909-938-9378 |
| UCRIM | Pacific Bell/TMC Communications (Cancelled) | UNE-Comp | C | California | 800-275-0014 |
| UCS | Unique Communications Solutions | Database Management System Provider VPC | A | USA - Nationwide | 702-216-0266 |
| UCSB | University of California Santa Barbara - CANCELLED | PBX/PS911/Shared Tenant | C | CA | 805-893-3446 |
| UCSD | University of California San Diego | PBX/PS911/Shared Tenant | A | USA - Nationwide | California | 858-964-8198 |
| UCSDH | UCSD Health System | PBX/PS911/Shared Tenant | A | CA | 619-543-6222 |
| UCTEL | UComtel Inc | VoIP Reseller VoIP Provider | A | USA - Nation Wide | 845-625-9000 |
| UCVH | Upper Connecticut Valley Hospital | PBX/PS911/Shared Tenant | A | USA - Nationwide | 603-237-4971 |
| UCVUL | Pacific Bell/Vertex Broadband (Cancelled) | UNE-Comp | C | California | 800-275-0014 |
| UCWMA | Pacific Bell / Anew Telecommun. Cor. (Cancelled) | UNE - Comp. | C | CA | 800-275-0014 |
| UDAC | USDATANET (INACTIVE) | Facility | C | NY | 315-952-8574 |
| UDALS | West Safety Services | PBX/PS911/Shared Tenant | A | 4807198557 | 4807198557 |
| UDT | United Data Technologies Inc. | VoIP Provider | A | USA - Nationwide | 800-882-9919 |
| UEA | Sun-Tel USA (INACTIVE) | CLEC Reseller, CLEC UNE | C | FL, KY | 904-731-9995 |
| UEM | CynergyComm.net Inc. - CANCELLED | CLEC Facility | C | MI | 888-257-1042 |
| UFT | United Farmers Telephone/Evertek | ILEC | A | IA | 800-242-0154 |
| UHART | University of Hartford | PBX/PS911/Shared Tenant | A | CT | 860-768-7985 |