| CoID | Company | Type | Status | States Served | 24X7 Phone |
| USS | United States Steel Corporation - CANCELLED | ILEC | C | USA | 412-433-1574 |
| USSP | United States Special Police (USSP) | PBX/PS911/Shared Tenant | A | DC | MD | MO | PA | VA | 202-600-4815 |
| USTC | Union Springs Telephone Co. Inc. | Facility | A | AL: Union Springs | Perote | Midway | Fort Davis | 334-738-2114 |
| USUHS | Uniformed Services University of the Health Svc | Other - (must identify below) | PS-ALI | A | MD | 301-319-0579 |
| USUNW | US Unwired (Cancelled) | Wireless | C | TX, LA, AL, FL, MS, AR, TN | 337-310-3121 |
| USWC | Qwest (formerly US West Communications) (Cancelled) | Tel. Co. | C | AZ, CO, ID, IA, MN, MT, NE, NM, ND, OR, SD, UT, WA, WY | 800-357-0911 |
| USX | US Xchange L.L.C. | CLEC Facility | A | IL | IN | MI | WI | 800-525-6775 |
| UTC | United Telephone Company | ILEC | A | TN | 800-779-2227 |
| UTCO | Union Telephone Company | ILEC | A | WI | 715-335-6301 |
| UTEX | UTEX Communications Corp. - CANCELLED | Facility | C | TX | 281-222-6307 |
| UTFED | University of Texas - Office of Federal Relations | VoIP | A | DC | 202-955-9091 |
| UTIL | Utilimaster | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) PBX/PS911/Shared Tenant | A | IN | 574-848-2028 |
| UTMA | United Telephone Mutual Aid Corporation | Facility | A | ND | 701-256-1100 |
| UTNO | Universal Telecom LLC - CANCELLED | CLEC Reseller | PBX/PS911/Shared Tenant | VoIP Provider | C | LA | MS | 504-962-3511 |
| UTOL | University of Toledo - CANCELLED | PBX/PS911/Shared Tenant | C | OH | 419-530-2600 |
| UVAW | University of Virginia's College at Wise | PBX/PS911/Shared Tenant | A | | 276-328-2677 |
| UVMCV | Central Vermont Medical Center Inc. | PBX/PS911/Shared Tenant | A | VT | 802-371-4176 |
| UVOX | UniVoxx | VoIP Provider | | USA - Nationwide | 248-243-8959 |
| UYT | Utility Telephone Inc. | CLEC Facility | VoIP | A | ALL | 866-788-4548 |
| VACH | Vernon Advent Christian Home Inc. - CANCELLED | PBX/PS911/Shared Tenant | C | VT | 802-254-6041 |
| VALAZ | Valley Telephone Coop Inc | ILEC | A | AZ | NM | 520-678-3988 |
| VALED | VAL-ED Joint Venture LLP dba 702 Communications | CLEC Facility | A | MN | ND | 218-284-5702 |
| VALL | Valley Telephone | Facility | A | SD | 605-437-2615 |
| VALLI | Valliant Telephone Co | ILEC | A | OK | 580-933-4400 |
| VALOR | Valor Telecommunications, LLC (Cancelled - see WIN) | Facility | C | TX, OK, NM | 866-616-9900 |
| VALU | Ionex Telecommunications, Inc (Cancelled) | CLEC | C | TX, KS, MO, OK | 877-333-2555 |
| VANBE | VanBelkum - CANCELLED | VoIP Reseller | C | USA - Nation Wide | 616-301-7676 |
| VANE | Apollo Communications, LLC (Cancelled) | Facility | C | CO | 866-899-9349 |
| VANTG | Vantage Unified Communications | VoIP Provider | A | USA - Nationwide | 800-493-3750 |
| VATAX | Virginia Department of Taxation | VoIP Provider | A | USA | 804-371-0924 |
| VATEC | Virginia Tech | PBX/PS911/Shared Tenant | A | VA | 540-231-6780 |
| VATEN | Virginia RSA 10 Limited Partnership (Cancelled) | Cellular | C | VA | 540-984-5220 |
| VAUGH | Vaughnsville Telephone (Cancelled) | Facility | C | OH | 419-646-3431 |
| VAYA | Vaya Telecom Inc. | CLEC Facility | A | CA | 916-233-3112 |
| VBONE | Voxbone S.A. | VoIP Provider | A | USA | 322-808-0003 |
| VBS | Valor Business Solutions (CANCELLED) | Reseller | C | TX | 866-616-9900 |
| VBTC | Van Buren Telephone Company Inc. | ILEC | A | IA | 319-293-3187 |
| VCC | Venture Communications Corp | ILEC | A | SD | 605-852-2224 |
| VCCCD | Ventura/Oxnard College dialtone by Verizon - CANCELLED | PBX/PS911/Shared Tenant | C | CA | 800-773-7911 |
| VCD | Veracity Communications Inc. - CANCELLED | CLEC Facility | CLEC Reseller | VoIP | PBX | C | UT | 801-379-3000 |
| VCELA | Vanguard Cellular Systems, Inc. (Cancelled) | Cellular | C | FL, KY, ME, NY, OH, PA, WV | 303-581-5782 |
| VCI | VCI Company d/b/a Vilaire Communications(Cancelled) | Reseller | C | MN | 253-830-0051 |
| VCI55 | Volkswagen Credit Inc | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | A | CA | DC | GA | IL | MI | NJ | OR | TX | VA | WI | 866-456-3366 |
| VCL | Virginia Cellular LLC (CANCELLED-REFER TO ACIW) | Facility | C | Virginia | 540-801-9049 |
| VCO | Valence Communications Services (Cancelled) | Reseller | C | TX | 888-239-5266 |
| VCONN | Valley Connections | CLEC Facility ILEC VoIP Provider | A | AZ | NM | 800-421-5711 |
| VCR | Voice Runner Inc. - CANCELLED | CLEC Reseller | VoIP Reseller | C | USA | 713-278-2600 |
| VCTRX | Vcentrix Inc. - CANCELLED | VoIP Reseller | C | US - All | 781-501-5065 |
| VCU | ValuTel Communications Inc. | Reseller | A | TX | NM | 505-271-9008 |
| VCUNI | opt #2 | PBX/PS911/Shared Tenant | A | VA | 804-827-2227 |