A Local Reference Number (LRN) is the declarant's unique number for a consignment and cannot be duplicated. Each transit declaration requires a separate LRN.
When you create a TAD you generate an LRN, Local Reference Number. The LRN is presentedto Customs at the office of departure, normally the export port. Customs check and
authenticate it and promote the LRN in to an approved MRN (see below) and the goods are now
free to move. Can be authenticated away from the port if using Authorised Consignor approval.