Abstract: A system and method for selecting and generating telephone access numbers for limiting access to a telephone service. The system includes an auto-dialer having a system clock, a memory device, a processor, and a tone generator. The auto-dialer is used to transmit user-associated data to a telephone service. The system clock generates a system time and the memory device stores data and a plurality of telephone numbers, each of which is capable of accessing the telephone service at different times. The processor is electrically coupled to the system clock and to the memory device and can select the telephone number capable of accessing the telephone service at any moment in time as a function of the system time. The auto-dialer can also include a number generator operating according to a preselected pseudo random sequence, in electrical communication with the system clock and the processor, where the output of the system clock is used as a seed number to the number generator.