A method and system for using a tracking ID to facilitate the refunding of unused postage is provided. Information for a postage transaction, along with the tracking ID and an associated delivery status, is stored. This delivery status is updated when the mail piece carrying the tracking ID is delivered. Unused postage can be confirmed by retrieving the stored postage transaction information and determining from that whether there are duplicative postage transactions. The delivery statuses for the duplicative postage transactions can then be reviewed to determine whether the mail pieces associated with these postage transactions have been delivered. If not, one of the postage transactions may be refunded.