A portable cellular phone system is provided, wherein matched sets of algorithmically generated communication units are generated, each defining an increment of authorized communication. One set is stored on a system server, i.e. a service provider, and the pre-paid set is available for use within a portable cellular phone. The portable cellular phone, which is normally non-activated, automatically contacts the system server upon selective activation by the user, to initiate a call (outgoing or incoming). A voice recognition system allows the user to place calls and/or receive calls. During a call, the portable cellular phone and the system server allow authorized access to communication, while the communication units are decremented at the system server and at the portable cellular phone. The portable cellular phone typically has either an internal energy supply and storage for the pre-paid communication units, or a removable airtime cartridge, typically containing an energy supply and either the ability to store or to generate a set of pre-paid single use airtime communication units.