What Is a Contract of Affreightment (COA)?

What Is a Contract of Affreightment?

A Contract of Affreightment, commonly known as a COA, is a long-term cargo transportation agreement between a cargo owner and a shipowner. Under this agreement, the shipowner undertakes to carry an agreed quantity of cargo over a defined period, usually through multiple shipments.

Unlike a single voyage charter, a COA does not normally bind the parties to one named vessel. The shipowner is generally responsible for nominating suitable vessels during the contract period, while the cargo owner commits to providing the agreed cargo volume.

For example, a cement producer planning to export 300,000 MT of clinker from Türkiye to West Africa over twelve months may prefer a COA instead of negotiating a separate voyage charter for each shipment.

How Does a COA Work?

A typical COA defines the total cargo quantity, contract duration, loading and discharge regions, shipment frequency, freight basis and operational responsibilities. The exact schedule may be fixed in advance or arranged through periodic nominations depending on cargo readiness and vessel availability.

The cargo owner benefits from long-term freight visibility and vessel capacity planning. The shipowner benefits from a steady cargo program and better fleet employment planning. This makes COAs especially useful when both parties expect repeated shipments between similar regions.

COA vs Voyage Charter

A voyage charter covers one specific cargo movement between named ports, while a COA covers a broader cargo program over time. In a voyage charter, the vessel is usually fixed for a particular shipment. In a COA, the emphasis is on transporting the agreed cargo quantity rather than committing one specific vessel.

This difference gives COAs more flexibility, but also requires careful planning, clear nomination procedures and reliable communication between all parties.

Advantages of a COA

A COA can provide better freight stability, improved transport reliability and lower administrative workload. Instead of negotiating every shipment separately, cargo owners can operate under one master agreement.

For industrial exporters, this can support production planning, buyer commitments and budget control. For shipowners, a COA can secure regular cargo employment and strengthen long-term commercial relationships.

Challenges of a COA

The main challenge of a COA is market risk. If freight markets move strongly in one direction, either the cargo owner or shipowner may feel that the agreed terms are less attractive than the spot market.

COAs also require cargo volume discipline, operational coordination and realistic shipment planning. If production delays, port congestion or market disruptions occur, the contract may need careful management to avoid disputes.

When Should Cargo Owners Consider a COA?

A COA may be suitable when cargo volumes are predictable, shipments are repeated throughout the year and transport reliability is important. It is often used for clinker, cement, coal, fertilizers, grains, iron ore, steel products and other regular bulk cargo flows.

For occasional or one-off shipments, a voyage charter may remain the simpler and more practical option.

How Shipbrokers Support COA Negotiations

An experienced shipbroker can help evaluate market levels, compare spot and long-term freight options, identify suitable owners, negotiate commercial terms and coordinate vessel nominations.

For cargo owners, professional support is important because a COA is not only a freight agreement; it is also a long-term operational framework that can affect supply chain performance.