PURPOSE : A system and a method for offering a service to register/offer real estate transaction information using the online network and a cash receipt are provided to utilize real estate-related information as correct statistical real estate data in future by completely matching actual real estate transaction particulars with the opened real estate-related information, as the transaction information is integrally transferred and managed through the online network by using a cash receipt card settlement mode.CONSTITUTION : A real estate information repository(401) stores real estate transaction data received from the real estate transaction terminal. A real estate information processor(402) analyzes and edits the received real estate transaction data. An information security processor(403) processes a request with use of a public key encoding mode in case that the real estate information processor requests security for the information related to the real estate. An external interface processor(404) relays the information related to the real estate transaction, and buyer/seller information to an external system by extracting/formatting relay data and fixing a data transfer protocol. A network transferring/relaying part(405) transceives the transaction data to the external system and the real estate transaction terminal.? KIPO 2006