Our customers choose ISC Fax because of our network reliability, high fax delivery success rates and a dependable customer support team. We are proud to say some of the largest companies in the world have been our customers for over 30 years! One of the keys to our customer satisfaction and retention is our ability to deliver messages reliably to nearly any destination in the world. Other fax messaging services use VOIP technology and/or low cost telecomm carriers to deliver faxes, resulting in higher call drops and undelivered fax messages. ISC Fax uses multiple types of technology and vendors to maximize reliability.