Methods and systems for instant activation of virtual PBX services on a mobile device are disclosed. In one aspect, a user request for activating virtual PBX services is received on a mobile device. An available primary identification number for the virtual PBX services is retrieved from a telecommunication service provider (TSP). A user interface is presented on the mobile device including a first interface portion presenting the available primary identification number and a second interface portion configured to receive a user identifier. Upon receiving the user input specifying the user identifier and while the user interface is still presented on the mobile device, a user instruction for activating the virtual PBX services is received. Upon receiving the user instruction, the user identifier is sent to the TSP. Then, a confirmation is received from the TSP.