A system and method for handing off from a first network to a second network. A determination may be made as to whether an accessible base station of the second network is located in the vicinity of a user equipment based on information on a current location of the user equipment in the first network. An activation message may be generated with a first telephone number as a caller number when an accessible base station of the second network is located in the vicinity of the user equipment based on the determination result. The activation message indicates an initiation of a search for an accessible base station of the second network, and an accessible base station of the second network may be searched for when the activation message with the first telephone number is received. A handoff from the first network to the second network may then be executed when the accessible base station of the second network is located.