A separate billing system for BYOD service includes a business service server configured to provide a business service, a terminal configured to request a business service from the business service server, a billing policy server configured to store billing policy information, a BYOD service gateway configured to control the terminal to transmit and receive data with the business service server via an access device, and generate billing data according to the transmission and reception, and a separate billing server configured to analyze the billing data based on the billing policy information, and generate separate billing information.