A vessel sharing agreement, or VSA, is a contract under which container lines contribute ships to a joint service and allocate each other slots on every sailing. Each partner sells its allocation under its own bills of lading, so one physical vessel carries several carriers’ cargo.
VSAs are the building blocks beneath alliances and countless bilateral services: one partner might contribute three ships to a loop, another two, with slot shares to match. Slot charters, where a line simply buys space on another’s service without contributing vessels, achieve similar coverage without the tonnage.
For shippers the practical effect is separation of contract and steel: your carrier answers for the cargo under its bill even when a partner operates the ship. Documentation, cut-offs, and customer service follow your carrier; the sailing schedule follows the operator.
VSAs are why tracking must resolve the operating vessel: the same sailing appears under different service names and voyage numbers per partner, while AIS knows only one ship. TrackingMCP normalises the partners’ references onto the physical vessel in tracking, so a delay reads identically whether you booked with COSCO or CMA CGM.
A vessel sharing agreement, or VSA, is a contract under which container lines contribute ships to a joint service and allocate each other slots on every sailing. Each partner sells its allocation under its own bills of lading, so one physical vessel carries several carriers’ cargo.
The carrier that issued your bill of lading, regardless of who operates the ship. The operating line answers to its partners under the VSA, not to you directly.
In a VSA partners contribute vessels and swap slots; in a slot charter one line buys space on another’s service without contributing ships. Both put multiple carriers’ boxes on one vessel.
Resolve the operating vessel →
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More in Vessels, voyages & schedules: Blank sailing · Port omission · Transshipment · Feeder vessel · Voyage number · ETA, ETD, ATA & ATD · Vessel schedule reliability · Slow steaming · AIS (Automatic Identification System) · Draft (draught) · Carrier alliances · Browse all 106 terms →