| CoID | Company | Type | Status | States Served | 24X7 Phone |
| CCONN | Comtel Connect - CANCELLED | VoIP Provider | C | USA-Nation Wide | 601-408-8992 |
| CCOPA | Commonwealth Court of Pennsylvania - CANCELLED | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | C | PA | 717-255-1600 |
| CCOR | Coos County - CANCELLED | 9-1-1 Admin-CPE ALI | C | OR | 541-396-3121 |
| CCPD | Cerritos College Police Department | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | A | CA | 562-924-3618 |
| CCRH | Coeur d Alene Casino Resort Hotel | PBX/PS911/Shared Tenant | A | ID | 208-686-8944 |
| CCRTC | Endeavor Communications | Co-Op/Rural | Cable Digital | ILEC | A | IN | 765-795-4261 |
| CCS01 | Custom Computer Specialists | CLEC Reseller PBX/PS911/Shared Tenant VoIP Reseller VoIP Provider | | USA - Nationwide | 919-926-1830 |
| CCSI | Cloud Compliance Solutions | VoIP Reseller VoIP Provider | A | USA - Nationwide | 561-990-3810 |
| CCSIP | Advania Corporation | VoIP Reseller | A | USA - Nationwide | (718) 766 7960 |
| CCSNH | Community College System of NH | ILEC | A | NH | 603-724-7845 |
| CCSPT | Campuslink-PaeTec (Cancelled) | PBX | C | ALL | 734-975-8000 |
| CCSU | Caledonia Central Supervisory Union | PBX/PS911/Shared Tenant | A | VT | 802-684-3801 |
| CCSU8 | Essex Westford School District | PBX/PS911/Shared Tenant | A | VT | 802-279-8355 |
| CCSVA | Charlottesville City Schools - CANCELLED | PBX | VoIP Facility | C | VA | 434-245-2404 |
| CCSVT | Charlotte Central School | PBX/PS911/Shared Tenant | A | VT | 802-343-8712 |
| CCT | Coast to Coast Telecommunications (Cancelled) | CLEC | C | MI | 248-623-6700 |
| CCTC | Coon Creek Telecommunications - CANCELLED | CLEC Facility | C | IA | 319-454-6234 |
| CCTCI | Totelcom Communications LLC | ILEC | A | TX | 254-842-7039 |
| CCTEC | Cuba City Telephone Exchange Company | ILEC | A | WI | 608-744-2154 |
| CCUNY | Corning Credit Union | PBX/PS911/Shared Tenant; VoIP | A | NY | NC | PA | SC | 607-962-3144 |
| CCV | Cloud Choice Voice | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) VoIP Provider | A | FL | 561-935-6300 |
| CCVP | Crump Communications LLC | VoIP Provider | A | USA - Nationwide | 231-722-1866 |
| CDAID | City of Coeur d'Alene | PBX/PS911/Shared Tenant | A | ID | 208-666-5720 |
| CDIAL | CoreDial LLC | VoIP Reseller | A | USA - Nation Wide | 215-297-4400 |
| CDIST | Chaffey Joint Union High School District | 9-1-1 Admin-CPE ALI | PBX/PS911/Shared Tenant | A | CA | 909-238-7058 |
| CDL | Cellular Properties Inc - CANCELLED | Wireless/Cellular/PCS | C | IL | 217-499-6876 |
| CDP | Carolina Digital Phone | Nation Wide | A | USA - Nation Wide | 855-200-0311 |
| CDS | ComData Solutions Inc | Wireless/Cellular/PCS VoIP Reseller VoIP Provider | A | TX | 817-601-6600 |
| CDWOH | City of Delaware, Ohio (CANCELLED) | PBX/PS911/Shared Tenant, VoIP | C | Delaware, OH | 740-203-1111 |
| CEA | Chugach Electric Association Inc. | Other (must identify below) | Electrical Utility | A | AK | 907-762-4444 |
| CEC | Cutting Edge Computers | VoIP Reseller VoIP Provider | A | USA - Nationwide | 248-462-7000 |
| CEDA | CEDA(Inactive) | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP Only) | C | IL | 312-513-7112 |
| CEDAR | Cedar Communications LLC | CLEC Facility | A | IA | 563-452-4200 |
| CEDR | Cedarcrest Center for Children With Disabilities | PBX/PS911/Shared Tenant | A | NH | 603-358-3384 |
| CEDW | Cedar Wireless Inc. - CANCELLED | VoIP Provider | C | USA - Nation Wide | 909-581-4640 |
| CEI | CEI Networks, Inc.-Cancelled (see WINC) | Facility | C | PA | 717-733-1411 |
| CELL1 | Cellular One(Cancelled) | PBX | C | MD, VA | 800-773-7911 |
| CELSO | Telepak Inc d/b/a Cellular South / CSpire Wireless | Wireless/Cellular/PCS | C | AL | MS | TN | 800-772-8250 |
| CELXL | Cellular XL Associates, L.P. (Cancelled - See MEGGT) | Facility | C | MS | 601-402-6876 |
| CENCL | Centennial Wireless (CANCELLED) | Cellular | C | IN, MI, OH, LA, MS, TX | 219-750-3802 |
| CENGA | Central Georgia Technology LLC | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) VoIP Reseller | A | USA - Nationwide | 470-481-0400 |
| CENPR | Centennial de Puerto Rico - CANCELLED | CLEC Facility | CLEC Reseller | CLEC UNE | Internet Protocol Relay Provider | | C | PR | 787-717-9920 |
| CENSU | Census Bureau - CANCELLED | VoIP | C | MD | 301-763-2196 |
| CENTA | Antares Technology Solutions Holdco Inc dba Centaris | VoIP Reseller | A | USA - Nationwide | 231-838-9951 |
| CENTC | CentraCom Interactive | ILEC | A | UT | 435-427-3331 |
| CEPBT | EPB Fiber Optics | CLEC Facility VoIP Provider | A | GA | TN | 423-648-4662 |
| CERR | City of Cerritos | PBX/PS911/Shared Tenant | A | CA | 562-860-0044 |
| CES09 | Conway Elementary School - CANCELLED | PBX/PS911/Shared Tenant | C | NH | 603-447-8368 |
| CESU | Chittenden East Supervisory Union - CANCELLED | PBX/PS911/Shared Tenant | C | VT | 802-730-2772 |
| CET | Consolidated Communications of New York Company LLC f/k/a C | ILEC | A | NY | 916-746-3000 |