Abstract: Credit in a credit register of a franking meter is reset by telephone communication with a resetting terminal. A request for a selected credit amount is transmitted from the meter apparatus to the terminal and in response the terminal interrogates the meter to establish identity of the meter. The terminal locks the meter to prevent operation of the meter for franking while the resetting takes place. The terminal checks the validity of the reset request with customer records stored in the terminal and if valid transmits a reset signal which includes the credit reset amount and a pseudo-random number (TID) to enable the meter to reset its credit register. Upon completion of the resetting the meter sends a request including a random number for unlocking of the meter. The terminal requests the register values from the meter, each request including a random number. The meter transmits the register values together with the random number to the terminal.