| CoID | Company | Type | Status | States Served | 24X7 Phone |
| ATMC | Atlantic Telephone Membership Corp | Co-Op/Rural ILEC | A | NC | 910-754-1730 |
| ATN | All Tel Networks LLC | VoIP Provider | A | USA - Nationwide | 772-215-1140 |
| ATS | ATS Telecommunications (Cancelled) | Facility | C | TX | 888-326-3302 |
| ATSLC | ATS Services, LLC (Cancelled) | Reseller | C | Illinois Counties: Cook, Kane, Lake, McHenry, DuPage, Will | 888-675-6347 |
| ATTBB | Insight Phone of Kentucky, LLC (CANCELLED) | Facility | C | OH | 800-771-9124 |
| ATTCS | AT&T Consumer Services, Inc (Cancelled) | CLEC Facility | C | ALL | 888-249-4980 |
| ATTI | A-Tech Telecom, Inc. (Cancelled) | UNE | C | TX,KY,AR | 972-527-2488 |
| ATTIS | AT&T | CLEC Facility ILEC VPC | A | USA - Nationwide | 877-450-1990 |
| ATTLS | AT&T | CLEC Reseller | A | CA | NV | 800-275-0014 |
| ATTMO | AT&T Mobility | Wireless/Cellular/PCS | A | USA - Nation Wide | 800-635-6840 opt. 4 |
| ATTPS | AT&T (Cancelled) | PS ALI | C | National | 888-249-4980 |
| ATTSP | AT&T Mobility | Wireless/Cellular/PCS | A | USA - Nationwide | 800-635-6840 opt. 4 |
| ATTWS | AT&T Wireless Services, Inc. (CANCELLED-See CING) | Wireless | C | ALL States | 800-635-6840 |
| ATU | ATU Telecommunications (Out of Business) | Facility | C | Anchorage, Byrd, Indian, Girdwood, Portage, Hope, AK | 907-564-1642 |
| ATUED | Arkansas Tech University | PBX/PS911/Shared Tenant | A | AR | 479-968-0646 |
| ATZ | ATX Telecommunications Services (Cancelled) | Reseller | C | PA, NJ, DE | 610-668-3000 |
| AUBN | Knology Inc. | CLEC Facility | A | | 877-566-5649 |
| AUD | Audian Inc. | VoIP Reseller VoIP Provider | A | USA - Nation Wide | 844-611-6110 |
| AUSD | Azusa Unified School District | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) | A | CA | 626-967-6211 |
| AUSER | Anyuser, Inc. (CANCELLED) | VoIP | C | CA | 858-831-0500 |
| AUSW | CSC WIRELESS LLC dba. ALTICE MOBILE | Wireless/Cellular/PCS | A | USA - Nationwide | 866-232-5455 |
| AVADV | AVAD Technologies | VoIP Reseller | A | USA - Nationwide | 800-733-4165 |
| AVAYA | Avaya | VoIP Provider | A | USA - Nationwide | 866-462-8292 |
| AVDNE | Advanced VoIP Data | VoIP Provider | A | USA - Nationwide | 248-313-2300 |
| AVF | Avfuel Corporation | SIP softphones via 3CX system | A | USA - Nationwide | 313-789-1291 |
| AVH | Androscoggin Valley Hospital | PBX/PS911/Shared Tenant | A | NH | 603-723-9605 |
| AVILA | AVILA (CANCELLED) | PBX/Facilt | C | NY | 800-829-0420 |
| AVOIP | AT&T | CLEC Facility VoIP Provider | A | USA - Nationwide | 888-249-4980 |
| AVR | Avaria - CANCELLED | VoIP Reseller | C | USA - Nationwide | 919-559-9693 |
| AVTS | Aviation Technical Services dialtone by Verizon - CANCELLED | PBX/PS911/Shared Tenant | C | WA | 425-423-3444 |
| AWC | All West Communications | Facility | A | UT | WY | 435-783-4361 |
| AWCC | Allied Wireless Communications Corp - CANCELLED | Wireless/Cellular/PCS | C | USA | 720-733-5360 NOC |
| AWE | Awesome Communications, Inc. (CANCELLED) | Reseller | C | GA, SC, LA | 877-231-2881 |
| AWX | Altaworx | VoIP Provider | A | USA - Nationwide | 404-902-5668 |
| AX911 | AccessCom - CANCELLED | CLEC Facility | CLEC UNE | C | Lafayette | LA | 877-204-6024 |
| AXIAT | Axia Technology Partners - CANCELLED | VoIP Reseller | C | USA Nation Wide | 317-489-5544 |
| AXO | AXO Communications LLC | CLEC Facility | A | USA - Nationwide | 212 380-7974 |
| AXTL | ApexxTek | VoIP Reseller VoIP Provider | A | LA | 504-355-1601 |
| AXX91 | Axxess Networks LLC | VoIP Provider | A | USA - Nationwide | 610-833-9000 |
| AXXES | Axxess Healthcare Consult - CANCELLED | PBX/PS911/Shared Tenant | C | USA - Nation Wide | 2145757711 |
| AXXS | Blue Mountain Networks | CLEC Facility CLEC Reseller VoIP Provider | A | WA | 503-891-7578 |
| AYB | Al-Call Inc. | Facility | A | GA | 912-632-5911 |
| AZSOA | Lumen/State of Arizona | 9-1-1 Admin-CPE ALI (9-1-1 Jurisdiction/PSAP ONLY) PBX/PS911/Shared Tenant | A | AZ | 855-799-8898 opt 3 |
| AZTH | Aztech Communications - CANCELLED | CLEC Facility | C | AZ | 928-542-0568 |
| AZUSA | City of Azusa | PBX/PS911/Shared Tenant | A | USA - Nationwide | 626-244-8046 |
| BA812 | Brewster Academy | PBX/PS911/Shared Tenant | A | NH | 603-998-6952 |
| BAA1 | Barr Tell USA Inc. | CLEC Facility | VoIP Provider | A | USA | 917-549-0100 |
| BABO | Babson College | VoIP Provider | A | USA - Nationwide | 781-239-3999 |
| BAC1 | Bank of America/Merrill Lynch(Inactive) | ILEC | C | NY | 212-236-8992 |
| BACO | Baltimore County Government - CANCELLED | ILEC | VoIP Proivder | C | MD | 410-887-8200 |