One Time Seal requirement for Nepal transit goods mandates serial endorsement and mandatory customs verification in transit declarations. An additional One Time Seal (OTL) must be affixed by Indian Customs on Nepal-bound transit goods via Kolkata/Haldia, with the OTL serial number endorsed in the Customs Transit Declaration (CTD). Land Customs Station officers are required to verify the physical OTL and match its serial number against the CTD; such checking by Customs officials is mandatory and subject to strict compliance.