Abstract: A multiprocessor parcel postage metering system includes a system processor to which a scale subsystem processor, a postage printing subsystem processor and a peripherals subsystem processor may be connected. The processors share a common data bus over which data is transferred serially. The system processor accepts weight and status data transmitted from the scale subsystem processor over the serial data bus. The system processor operates on this data and keyboard entry data to calculate required postage as a function of parcel origin, parcel destination, class of service and selected special fees. Printer setting data is transferred to the postage printing subsystem processor over the serial data bus. Peripheral devices, such as a document printer or a parcel identification number counter, are controlled by data sent to the peripherals subsystem processor over the serial data bus.