| Canby Tel. Assn. | Canby Telephone Association | Canby, OR | Active |
| Cannon Valley Telecom Inc. | Cannon Valley Telecom, Inc. | Blue Earth, MN | Active |
| Cap Rock Telephone Cooperative, Inc. | - | Spur, TX | Active |
| Carbon/Emery Telcom | - | Orangeville, UT | Active |
| Carnegie Telephone Co. | Carnegie Telephone Company, Inc. | Carnegie, OK | Active |
| Carr Telephone Company | - | Branch, MI | Active |
| Cascade Communications Company | - | Cascade, IA | Active |
| Cascade Utilities Inc. | Cascade Utilities, Inc. | Estacada, OR | Active |
| Casey Mutual Tel. Co. | Casey Mutual Telephone Company | Casey, IA | Active |
| Cass County Telephone Company | Cass County Telephone | Harrisonville, MO | Inactive |
| Cass Telephone Company | - | Virginia, IL | Active |
| Cassadaga Telephone Corporation | - | Fredonia, NY | Active |
| Castleberry Tel. Co. Inc. | Castleberry Tel. Co., Inc. | Castleberry, AL | Active |
| Center Junction Tel. Co. | Center Junction Telephone Co., Inc. | Center Junction, IA | Active |
| Central Arkansas Telephone Cooperative, Inc. | Central Arkansas Telephone Cooperative | Bismarck, AR | Active |
| Central Montana Communications Inc. | Central Montana Communications, Inc. | Havre, MT | Inactive |
| Central Oklahoma Telephone Co., LLC | - | Davenport, OK | Active |
| Central Scott Telephone Company, Inc. | Central Scott Telephone | Eldridge, IA | Active |
| Central State Telephone Co. | TDS Telecom | Madison, WI | Active |
| Central Texas Telephone Cooperative, Inc. | Central Texas TeleCommunications | Goldthwaite, TX | Active |
| Central Utah Telephone, Inc. | - | Fairview, UT | Active |
| CenturyTel - Central WI | CenturyTel of Central Wisconsin, LLC | Monroe, LA | Active |
| CenturyTel Midwest-Michigan, Inc. | CenturyTel of the Midwest - Michigan, Inc. | Monroe, LA | Active |
| CenturyTel of Eastern Oregon, Inc. | CenturyTel of Eastern Oregon, Inc. | Monroe, LA | Active |
| CenturyTel of Adamsville, Inc. | - | Monroe, LA | Active |
| CenturyTel of Alabama, LLC | - | Monroe, LA | Active |
| CenturyTel of Arkansas, Inc. | - | Monroe, LA | Active |
| CenturyTel of Central Arkansas, LLC | CenturyTel of Jacksonville & Mammoth Spring, LLC | Monroe, LA | Active |
| CenturyTel of Central Indiana, Inc. | - | Monroe, LA | Active |
| CenturyTel of Central Louisiana, Inc. | CenturyTel of Central Louisiana, LLC | Monroe, LA | Inactive |
| CenturyTel of Chatham, LLC. | CenturyTel of Chatham, LLC | Monroe, LA | Inactive |
| CenturyTel of Chester, Inc. | - | Monroe, LA | Active |
| CenturyTel of Claiborne, Inc. | - | Monroe, LA | Active |
| CenturyTel of Colorado, Inc. | - | Monroe, LA | Active |
| CenturyTel of Cowiche, Inc. | - | Monroe, LA | Active |
| CenturyTel of Eagle, Inc. | - | Monroe, LA | Active |
| CenturyTel of East Louisiana | CenturyTel of East Louisiana, LLC | Monroe, LA | Inactive |
| CenturyTel of Evangeline, Inc. | CenturyTel of Evangeline, LLC | Monroe, LA | Active |
| CenturyTel of Fairwater-Brandon-Alto, Inc. | CenturyTel of Fairwater-Brandon-Alto, LLC | Monroe, LA | Active |
| CenturyTel of Forestville, Inc. | - | Monroe, LA | Active |
| CenturyTel of Idaho, Inc. | - | Monroe, LA | Active |
| CenturyTel of Inter-Island, Inc. | - | Monroe, LA | Active |
| CenturyTel of Lake Dallas, Inc. | - | Monroe, LA | Active |
| CenturyTel of Larsen-Redfield, Inc. | CenturyTel of Larsen-Readfield, Inc. | Monroe, LA | Active |
| CenturyTel of Michigan, Inc. | - | Monroe, LA | Active |
| CenturyTel of Midwest-Kendall, Inc | CenturyTel of the Midwest - Kendall, Inc. | Monroe, LA | Active |
| CenturyTel of Minnesota, Inc | CenturyTel of Minnesota, Inc. | Monroe, LA | Active |
| CenturyTel of Missouri, LLC | CenturyTel of Missouri LLC | Monroe, LA | Active |
| CenturyTel of Monroe County, Inc. | - | Monroe, LA | Active |
| CenturyTel of Montana, Inc. | - | Monroe, LA | Active |