Whose responsibility is it to declare the LRN? The haulier or the exporter?

The LRN is input into NCTS by the declarant.

The exporter, agent, trader (or haulier) must ensure that the LRN is activated at the office of departure or by the authorised consignor. All LRNs in one truck must be presented to the Office of Departure if not being processed by the authorised consignor .