A method for establishing a hybrid voice session between a mobile device and a VoIP device is disclosed. A caller using a mobile device in a mobile network initiates a request for a voice session by clicking on a virtual identifier, e.g. an email address, provided for the callee in an address book on the caller's mobile device. If the callee is online, then the request is enabled. In one embodiment, the request is enabled by creating a call registration record using a mobile data network. In another embodiment, the request is enabled by having the caller interact with an IVR system. In yet another embodiment, a caller can interact with the IVR system from any type of telephone device. The callee is notified regarding the voice session, and if accepted, the hybrid voice session is established via a voice channel and a VoIP channel.