Shippers frequently engage the services of freight or forwarding agents, namely, persons who undertake for a reward to have the goods carried and delivered at their destination. The services of these persons are ordinarily engaged when the carriage of the goods involves successive carriers or use of successive means of transport.

A forwarding agent makes contracts of carriage for his principal. He may be a carrier or he may be merely a forwarding agent. When a carrier enters into a contract with the shipper by which he undertakes to carry goods in circumstances that involve an obligation on his part to hand over the goods to another carrier, he may be regarded as acting to some extent in the capacity of a forwarding agent. Conversely, when a forwarding agent carries the goods himself, he is to that extent a carrier and incurs the liabilities of a carrier.

In common-law jurisdictions a forwarding agent who is not a carrier is not responsible for what happens to the goods once they are handed over to a carrier with whom the forwarding agent has made a contract for his principal. By his transaction with the carrier, the forwarding agent establishes a direct contractual relationship between his principal and the carrier. Under the principles of the law of agency, the forwarding agent is under obligation toward his principal to conclude the contract on the usual terms. He is under no obligations, in the absence of an express contractual provision, to insure the goods. If, exceptionally, a forwarding agent acts as a carrier throughout the journey and uses other carriers on his own account, he is liable to the owner for any loss or damage to the goods during carriage. The extent of his liability depends on whether he is a common carrier or a contract carrier. If he is a common carrier, his liability to the owner of the goods may be heavier than the liabilities he can enforce against the carriers he has engaged.

In civil-law jurisdictions forwarding agents are clearly distinguished from carriers, and the contracts they make are clearly distinguishable from contracts of carriage. The profession of a forwarding agent, however, is not exclusive; thus, most frequently, carriers qualify as forwarding agents and vice versa. A forwarding agent has ordinarily a privilege on the goods under his control that is much broader and more effective than the privilege of the carrier. He has, in the absence of contrary contractual provision, freedom of choice of the means of transport and of particular carriers. His main obligation is to have the goods carried to their destination and delivered to the consignee. In the discharge of this obligation, he is generally entitled to engage the services of another forwarding agent. The forwarding agent is liable to his principal for any violation of his obligations resulting from negligence or intentional misconduct. He is relieved from liability if he proves that the loss or damage was occasioned by irresistible force. The liability of the forwarding agent for negligence may be excluded by contractual stipulations but not his liability for grave fault and intentional misconduct. A forwarding agent is considered as a carrier to the extent that he carries the goods himself, and to that extent he incurs the liabilities of a carrier. In contrast with the rule in common-law jurisdictions, the forwarding agent in civil-law countries is fully responsible for loss or damage suffered by the goods in the hands of carriers that the forwarding agent has engaged for the performance of the contract with his principal, unless the services of the particular carrier were requested by the principal. The liability of the forwarding agent does not exceed that of the carrier he has engaged, and, if the carrier is exonerated by virtue of an excepted cause, so is the forwarding agent.

Mixed-carrier transportation

The expression mixed-carrier transportation refers to situations in which goods are carried to their final destination by two or more means of transport, such as road and sea or rail, sea, and air. There are at least two possibilities. The successive carriers may have no common juridical link, as when the shipper has contracted with each carrier independently or when the shipper has contracted with a forwarding agent. In these cases, each carrier is subject to his own regime and has his own rights and duties toward the shipper or forwarding agent. A second possibility is that the successive carriers may be bound by a common juridical link toward the shipper or owner of the goods by virtue of directly applicable legal or contractual provisions or by virtue of the fact that the goods travel under a single document of transport, as a through bill of lading. In these cases, municipal laws in civil-law jurisdictions tend toward the irreconcilable aims of subjecting each carrier to his own regime and, at the same time, holding all carriers solidarily liable. In domestic carriage in common-law jurisdictions, the liability of each carrier is ordinarily determined by application of the rules governing carriage by two or more carriers.

Mixed-carrier transportation in international commerce under a through bill of lading or similar document has been dealt with in international conventions. A through bill of lading covers carriage of goods by two or more successive carriers or by two or more means of transport. It is issued by the first carrier and constitutes a single title to the goods. Under a purely maritime through bill of lading, successive carriers are equally bound, unless the contrary has been stipulated. Solutions differ, however, when carriage is effected by two or more means of transport. Under the Berne Railroad Conventions for the carriage of goods, carriage by rail and sea may be subject to the rules governing railroad carriage at the option of the contracting states, unless reservation has been made by them for application of certain rules of maritime law to the portion of sea carriage. Since these conventions may be entirely inapplicable to the portion of sea carriage, interested carriers and international organizations have concluded agreements for a uniform, legal regime of rail and sea carriage. In fact, accords have been concluded among United States and Canadian railway and ocean-shipping companies for application of the rules of the Brussels Convention of 1924 to goods carried under through bills of lading by rail and sea. The rules of the Warsaw Convention for carriage of goods by air apply always to the portion of air carriage and to that portion only, but the International Air Transport Association and the International Union of Railways have concluded agreements for carriage by rail and air under a single document. Only the Geneva Convention of 1956 has undertaken to establish rules applicable to all means of transport under a single document. The convention provides, however, that, if damage has been incurred in a portion of the journey other than road carriage, the carrier shall be subject to his proper law. This convention may conflict with the Berne Conventions and does conflict with the Warsaw Convention to the extent that carriage by air is subjected to the Brussels rather than the Warsaw Convention.

In the Western world, the transport of goods is divided between public and private enterprise. The basis of the legal relationship between a carrier and his customer is the same whether the carrier is a public corporation, a local authority, or a private corporation or individual. The law of carriage of goods governs the rights and duties of the shipper, carrier, and consignee.