Method and system for providing a seamless handoff between communication networks

Disclosed is a method that includes initiating a handoff (403) by transmitting a handoff (403) start message to a mobility manager by a first mobile station. The first mobile station is in a call with a second mobile station and moving out from a first communication network to a second communication network. The handoff start message comprises a first call context. The first communication network comprises various network entities such as a SIP server, mobility manager, and the like. The method further includes creating a SIP instance (404) in the mobility manager to hold the first call context. Further, a handoff extension call is placed (405) by the first mobile station to the SIP server via the second communication network and once the handoff extension call is placed, an INVITE message is sent (406) from the SIP server to a preconfigured extension of the mobility manager. The INVITE message comprises a second call context. Thereafter, the handoff extension call is redirected (409) from the second communication network to the first communication network via the mobility manager, in response to the INVITE message received by the preconfigured extension of the mobility manager.