Interline shipping refers to a freight arrangement where a single shipment is handled by two or more different carriers during its transit, with a formal interline agreement governing the transfer of the freight and revenue sharing between the participating carriers. Unlike a single-carrier shipment, an interline shipment moves through handoffs between different carrier networks to reach its final destination.
Why Interline Arrangements Exist
No single carrier operates everywhere. When a shipper needs service to a location outside a carrier’s own network, the carrier may arrange an interline transfer with another carrier that serves the destination. This allows carriers to offer broader geographic coverage than their own network supports, while shippers benefit from a single bill of lading and one point of contact for the shipment.
Interline in LTL Freight
In LTL freight, interline is common for shipments to remote areas not served by major national carriers. The origin carrier accepts the freight and provides a through bill of lading, then transfers the shipment to a partner carrier at an agreed junction point. Interline transfers add handling events — increasing the probability of transit damage or delay — which is why carriers typically prefer direct service when available and reserve interline for points outside their network.