Abstract: An information transport system for conveying information between a franking meter machine and a Post Office equipment includes a unit having a non-volatile read/write memory which may consist of an EEPROM which can be transported between the meter and the equipment. When the unit is inserted in the franking machine a transaction code is verified by comparison with a registered code and information transfer is effected. The machine then generates a new code and stores it in a register. Upon return of the unit to the Post Office, the equipment responds to the transaction code stored in the unit to generate a new code corresponding to the new code generated and stored in the meter machine.