Shipper-Owned Containers (SOC)

What Is a Shipper-Owned Container?

A Shipper Owned Container (SOC) is a freight container owned or leased by the shipper, cargo owner, freight forwarder or logistics operator rather than the shipping line carrying it.

The shipping line provides space on the vessel, but the SOC owner supplies the container. After delivery, the container remains with its owner or consignee rather than being returned to the carrier’s equipment depot.

This differs from a Carrier Owned Container (COC). A COC belongs to, or is leased by, the shipping line. It must normally be collected, loaded, unloaded and returned within agreed time limits. Late return can lead to detention, demurrage, storage and repositioning charges.

Shipping Containers of London can supply suitable new and used containers for businesses considering SOC ownership. Suitability for storage does not automatically imply suitability for international maritime transport; the intended use must be confirmed before purchase.

Important Legal and Financial Disclaimer

SOC vs Carrier Owned Container

An SOC can reduce exposure to carrier equipment detention, but it does not make a shipment free from all delay-related charges. Port storage, terminal handling, customs examination, haulage waiting time and cargo-related demurrage may still apply.

When SOC Ownership Can Make Sense

SOCs are often used for project cargo, remote destinations, long unloading periods and regular trade routes where equipment control matters.

Remote and long-term projects

Engineering, energy, construction and aid projects may need to keep cargo inside the container for weeks or months. Buying a container can be more practical than using carrier equipment that must be returned quickly.

Storage after delivery

The consignee can unload the cargo gradually and retain the SOC for secure site storage. The container may later be reused, repositioned or converted, subject to planning, building and safety requirements.

Regular shipping programmes

Businesses with predictable cargo flows may use their own equipment to reduce reliance on carrier container availability. The owner must still arrange empty repositioning, storage, maintenance and tracking between shipments.

Special cargo

Open-top, flat-rack, side-opening, high-cube and refrigerated containers can support cargo that does not fit a standard dry container. Carrier approval remains essential, especially for out-of-gauge, heavy, powered or temperature-controlled equipment.

CSC Plates and Container Safety

The CSC plate is the safety approval plate fitted under the International Convention for Safe Containers. The Convention was developed to maintain safety during container transport and handling and to support common international test and strength requirements.

The International Maritime Organization’s CSC information sets out the international framework. In Great Britain, freight container safety duties are supported by the Freight Containers (Safety Convention) Regulations and guidance from the Health and Safety Executive.

A plate alone does not prove that a container is currently safe. The owner must check that the plate is genuine and legible, that the container remains within an approved examination scheme or the next examination date, and that its physical condition is suitable for the planned journey.

Typical inspection points include:

• Corner posts, corner castings and structural rails.
• Roof, side panels and end frames.
• Doors, hinges, locking bars and seals.
• Floor condition and load-bearing areas.
• Welds, corrosion, distortion and previous repairs.
• Container identification and safety markings.

A container described as wind and watertight keeps out normal wind and rain, but that storage grade does not confirm cargo-worthiness or approval for sea transport. A qualified inspection may be required before a used container can enter international service.

Weight, Packing and Verified Gross Mass

Tare weight is the weight of the empty container. Payload is the maximum permitted cargo weight. The combined weight of the container and its cargo is the gross mass.

The shipper must not exceed the limits shown on the container’s safety approval plate. Road vehicle, axle, crane, terminal and vessel limits may impose lower practical limits.

For packed containers carried by sea, SOLAS rules require a Verified Gross Mass (VGM) before loading. UK guidance confirms that the declared mass includes the cargo, packing materials and container tare weight. See the UK Government guidance on verified gross mass.

The cargo must be packed, blocked, braced and distributed correctly. Poor weight distribution can damage the floor, affect road stability and create lifting or stacking risks. Dangerous goods require additional classification, packaging, marking and documentation.

Container Numbers and Carrier Acceptance

An SOC used in international transport needs clear and valid identification. The owner should confirm container numbering, ownership markings and check-digit requirements with the carrier and relevant registration body.

Do not assume that a former carrier’s logo, prefix or fleet number can remain in use after a container changes ownership. Incorrect identification can cause booking mismatches, terminal rejection, customs delays and disputes over liability.

Before loading, provide the carrier or freight forwarder with the container number, size and type, tare weight, CSC details, examination status, cargo description, gross mass and any dangerous-goods information. Obtain written confirmation that the carrier accepts SOC equipment on the selected route.

Choosing a Suitable SOC

Standard 20ft and 40ft containers suit most dry cargo. High-cube containers provide an extra foot of external height for bulky loads. Open-top and flat-rack containers support cargo loaded by crane or cargo that exceeds standard dimensions.

A one-trip container is normally manufactured overseas, used for a single loaded journey, and then sold. It often has limited wear and a recent CSC plate. Used containers cost less, but condition, repair history and examination status vary.

Check the following before purchase:

• The seller has the right to sell the container.
• The identification number matches the documents.
• The CSC plate and examination status are suitable.
• The container type matches the carrier booking.
• The floor and structure are suited to the intended payload.
• Modifications have not reduced structural strength.
• Insurance covers the equipment, cargo and intended route.

Delivery and Site Requirements in London

Shipping Containers of London can arrange delivery using a HIAB vehicle, which is a lorry fitted with a hydraulic loading crane. Safe delivery requires enough road width, operating height and firm ground for the vehicle and stabiliser legs.

The site should provide level hardstanding, such as concrete, compacted stone or suitable load-bearing pads. Avoid soft ground, buried services, low branches and overhead cables. A container should normally be supported at its corner castings so the doors remain square and operate correctly.

Tell Shipping Containers of London about gates, parked vehicles, restricted turns, controlled roads and lifting obstructions before delivery. Maritime loading is separate from local HIAB delivery, so export haulage and port handling must be planned with the freight forwarder.