A method and apparatus for performing session release are provided. For a transferred communication session between a plurality of wireless transmit/receive units (WTRUs) and a remote device, wherein at least one of the WTRUs performs the transferred communication session in association with a first Internet Protocol Multimedia Subsystem (IMS) and at least one other of the WTRUs performs the transferred communication session in association with a second IMS, session release may include releasing the transferred communication session, a portion thereof, one or more of the WTRUs, or a collaborative session associated with the transferred communication session while maintaining service continuity. Any one of the plurality of WTRUs or the remote device may initiate the session release by transmitting a release request. Any one of the plurality of WTRUs may control the transferred communication session and may modify or reject a release request.