An apparatus and method for transferring network access information of smart household appliances are provided. The apparatus includes a detection unit for detecting whether a public IP address of an external interface of an indoor IP sharer has changed. An extraction unit is configured to, if the public IP address of the external interface has changed, extract network access information of a smart household appliance connected to an internal interface of the indoor IP sharer, the network access information being updated together with change in the public IP address. An encryption and generation unit encrypts the network access information using a pre-stored encryption key, and generates data to be transmitted to a smart grid service provider server using the encrypted information and an ID of a customer user. A transmission unit transmits the data generated by the encryption and generation unit to the smart grid service provider server.