Abstract: A retrofit, automatic audit system for a door-access, coin-operated newspaper rack machine is disclosed. The system operates in conjunction with the standard door-lock mechanism and includes a retrofit purchase-mechanism mounted on the machine. The purchase-mechanism includes an electromechanical audit structure which is operatively connected to the purchase-mechanism and door-lock mechanism and monitors and records service and transaction audit data involving the purchase-mechanism. A portable data transfer unit is proximity coupleable with the audit structure for acquiring audit data therefrom. The system includes proximity activation through magnetic structure which causes the audit structure to shift from a data acquisition mode to an automatic data transfer mode when a data transfer unit is proximity coupled thereto. Communication means between the audit structure and the data transfer unit includes an optical structure providing communication therebetween.