<Page> Exhibit 23 INDEPENDENT AUDITORS' CONSENT We consent to the incorporation by reference in Registration Statement No. 333-46954 of Covista Communications Inc. on Form S-3 and Registration Statement No.'s 33-64611, 333-79165, 333-72720, 333-82616, and 333-82620 of Covista Communications, Inc. on Form S-8 of our report dated May 15, 2003, appearing in this Annual Report on Form 10-K of Covista Communications, Inc. for the year ended January 31, 2003. /s/ Deloitte & Touche, LLP Atlanta, Georgia May 15, 2003