Switch-based intelligent-networked pre-paid telephone calling card service system having bailout to telephone operators

An improved implementation of pre-paid telephone calling cards uses a switch-based intelligent network (IN) for automated processing of pre-paid calling card account transactions. Calling card account number, corresponding PINs, account status information and others are stored in tables maintained by one or several switches for routing calls, each switch nominally including a Service Switching and Control Point (SSCP), an Originating Call Processor (OCP), and a Terminating Call Processor (TCP). In the preferred embodiment, each switch also contains an Operator Service System (OSS) for allowing a telephone operator to direct call processing either by choice of the customer (direct dial to the operator) or as backup to the automatic processing capability of the SSCP. The system bails out to the OSS when one of the following occurs: the customer demands a bailout; the customer fails to enter any information when prompted; the customer enters incorrect or invalid information more than a predetermined number of times; and the pre-paid calling card account balance is insufficient for the customer's proposed telephone call.