Method of processing mailpieces using customer codes associated with digital fingerprints

A method of processing mailpieces to which Customer Applied Identifier (CAI) codes have been assigned by a sender of the mailpieces to each mailpiece, and for which first fingerprint V_Id and address information Ad are known by the sender and compiled by the sender in correspondence with a CAI code and recorded by the sender in a file F, CAI codes being used for remotely tracking the mailpieces while the mailpieces are passing through a postal operator's postal sorting system, comprising the steps of:

• a) receiving, in parallel with a batch of mailpieces provided by the sender, CAI codes respectively assigned to said mailpieces by the sender and the file F, said CAI codes being not printed on the mailpieces,
• b) recording said CAI codes in memory in the sorting system in correspondence with first digital fingerprints or image signatures of the surfaces of the mailpieces prior to a first pass of the mailpieces through the postal sorting system,
• c) feeding the mailpieces into the postal sorting system in a first sorting pass, and further performing during said first sorting pass the steps of:
• d) forming, for each current mailpiece passing through the postal sorting system, an image of the surface of the current mailpiece that bears a postal address block,
• e) deriving a current fingerprint from the respective image,
• f) searching in the memory for a match between said current fingerprint and a recorded first fingerprint,
• g) upon detection of a match, retrieving from the memory the CAI code and address information Ad corresponding to the current mailpiece using the mailpiece first fingerprint V_id provided by the sender in file F in correspondence with said CAI codes prior to the first sorting pass, and
• h) recording in the memory location information corresponding to the retrieved CAI code, the location information including postal sorting machine identification data and a time at which the current mailpiece passed through the postal sorting machine.