All shipping lines have contracts of carriage, called ‘Bills of Lading' which govern the relation between the shipper, carrier, and the consignee. Due to the fact that in some cases neither the shipper nor the consignee complies with their obligations to provide the shipping carrier with the containers back empty, a specific condition concerning ‘demurrage' applies to the merchant (shipper/consignee) who will be charged due to his direct fault or negligence if he fails to give containers back empty to the carrier, since such malpractice can cause enormous losses to the carrier who will be unable to make use of his containers. 

The Essential Role of the Bill of Lading