An offline code-based reload device and method for adding value to a reconfigurable memory storage means in a portable storage medium. Reload is effected using a reload device not directly connected by telephone or any other communication network to a value supplier. The system uses a "one time use number" ("OTN") generated by a computer program containing an algorithm containing information on the value to be added and a transaction sequence number ("TSN"). Upon presentation of the portable storage medium to the reload device and entry of the OTN into a numeric keypad, the reload device decodes or disassembles the OTN to verify its authenticity, validate that it was created for the specific portable storage medium presented to the reload device and to verify through the TSN that the OTN has not been previously used to add value from the receiving reload device or any other reload device. The reload device further extracts the value from the OTN, adds the value to a selected purse on the portable storage medium and loads a new TSN to the portable storage medium.