Exhibit 21 SUBSIDIARIES I. 100% owned subsidiaries of Horizon Telcom, Inc.: A. The Chillicothe Telephone Company, an Ohio corporation. B. Horizon Services, Inc., an Ohio corporation. C. Horizon Technologies., an Ohio corporation. II. Horizon Telcom, Inc. is a majority owner of: A. Horizon PCS, Inc., a Delaware corporation, Horizon PCS, Inc. owns 100% of: 1. Horizon Personal Communications, Inc., an Ohio corporation. 2. Bright Personal Communications Services, LLC, an Ohio limited liability company.