# | A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
| Company Name | Address | Phone | Fax |
| Inland Telephone Company | P.O. Box 171 Roslyn Washington 98941 | 509-649-2211 | 509-649-3300 |
| Inter-Community Telephone Co., LLC | P.O. Box 8 Nome North Dakota 58062-0008 | 701-924-8815 | |
| InterBel Telephone Cooperative, Inc. | P.O. Box 648 Eureka Montana 59917 | 406-889-3311 | 406-889-3787 |
| Interior Telephone | 201 East 56th Ave. Anchorage Alaska 99518 | ||
| Interstate 35 Telephone Company | P.O. Box 229 Truro Iowa 50257-0228 | 712-824-7231 | 712-824-2345 |