Shipper’s Own Containers: Costs, Compliance and Documentation

What Is a Shipper’s Own Container?

An SOC is a container owned or leased by an exporter, importer, freight forwarder, beneficial cargo owner or another party outside the ocean carrier’s equipment fleet.

The shipping line transports the loaded container by selling space on its vessel. However, the line does not usually accept responsibility for maintaining, inspecting or storing the SOC after delivery.

A Carrier Owned Container, or COC, belongs to or is leased by the shipping line. The customer normally collects it, loads it and returns it to an approved depot within an agreed free-time period.

When Can an SOC Be Useful?

SOCs are often considered for remote projects, irregular trade routes and deliveries where the container will remain at the destination for an extended period.

• Long-term storage: The consignee can keep the container without returning it to the shipping line.
• Remote destinations: An SOC avoids difficult or expensive empty-container repositioning.
• Project cargo: Construction, mining and engineering businesses may use the container as secure site storage after unloading.
• Equipment control: The owner selects the container’s size, condition and internal configuration.
• Repeated movements: A business may reuse the same equipment across suitable trade routes.

Ownership does not remove port storage, customs inspection, terminal handling or documentation charges. Some carriers also apply an SOC surcharge or offer different freight rates because they must approve and process equipment outside their own fleet.

CSC Plates and Safety Examinations

The International Maritime Organization’s International Convention for Safe Containers establishes safety approval and structural testing requirements for containers used in international transport.

An approved container carries a Safety Approval Plate, commonly known as a CSC plate. The plate records information such as the approval reference, date of manufacture, maximum operating gross mass and allowable stacking or racking values.

The plate is not a guarantee that a damaged container remains safe. The owner must maintain the container and arrange appropriate examinations. A container may operate under a periodic examination scheme or an Approved Continuous Examination Programme, commonly shortened to ACEP.

Check the examination date or ACEP details before purchase. Significant damage to corner posts, top or bottom rails, cross-members, corner fittings, doors or structural welds should be assessed by a competent inspector.

Documentation Checklist Before Purchase

1. Proof of ownership: Obtain a signed invoice or bill of sale that identifies the seller, buyer, and container number.
2. Container identity: Check the identification number, type, size, tare weight and maximum gross mass.
3. CSC details: Photograph the plate and confirm the examination date or ACEP approval.
4. Inspection report: Check the structure, roof, walls, floor, doors, seals, corner fittings and previous repairs.
5. Seller authority: Confirm that the seller has the right to transfer the container and that no leasing company retains an interest.
6. Carrier acceptance: Obtain written confirmation from the shipping line and terminals that they will accept the SOC.
7. Insurance: Confirm cargo, container, third-party liability, salvage and general average cover.

Export and Shipping Checklist

1. Prepare a commercial invoice and accurate packing list.
2. Confirm the correct commodity codes, customs value and country of origin.
3. Check whether licences, certificates or sanctions controls apply.
4. Submit the required export customs declaration.
5. Ensure the booking clearly identifies the container as an SOC.
6. Provide the container number and current CSC examination details.
7. Calculate and submit the Verified Gross Mass before the carrier’s cut-off.
8. Prepare accurate bill of lading instructions.
9. Retain inspection, ownership and customs records.

UK guidance states that the shipper is responsible for providing the Verified Gross Mass of a packed container. This can be established by weighing the packed container or by using an approved calculation method that includes the cargo, packaging, securing materials and container tare weight.

UK Import and Customs Checklist

1. Confirm that the importer has the correct EORI number.
2. Appoint a customs agent and agree whether representation is direct or indirect.
3. Submit an accurate import declaration within the applicable deadline.
4. Confirm duty, import VAT and product-specific controls.
5. Arrange the bill of lading, delivery order and terminal release.
6. Keep evidence of container ownership available.
7. Confirm the separate customs treatment of the container itself.

Reusable containers entering Great Britain may need to be entered into free circulation or declared under Temporary Admission, depending on ownership, intended use and whether the equipment will be re-exported. Do not assume that clearing the cargo also settles the container's customs status.

BIFA guidance recommends clearly defining the authority, responsibilities and liabilities of customs agents and their customers. Using an agent does not remove the need to provide complete and accurate shipment information.

Worked SOC Cost-Benefit Calculations

Example One: Storage at the Consignee’s Site

Assume a container will remain at the customer’s site for 100 days. The carrier allows 10 free days, followed by an equipment charge of £45 per day.

COC cost: 90 chargeable days × £45 = £4,050.

Under these assumptions, the SOC saves £2,150. The estimated break-even point is approximately 43 chargeable days: £1,900 divided by £45.

Example Two: Container Delayed Inside the Port

Assume the terminal provides five free days, followed by storage at £70 per day. A 30-day port stay creates 25 chargeable days.

Port storage: 25 × £70 = £1,750.

Port storage can apply to both SOC and carrier-owned equipment. If the COC also attracts £45 per day for 25 days, its combined example cost is £2,875. The SOC would incur £1,750 in port storage plus the £1,900 net ownership cost, for a total of £3,650.

In this shorter example, buying the SOC costs £775 more. Ownership is not automatically the cheapest choice. The result depends on the storage location, delay period, resale value and carrier tariff.

Frequently Asked Questions

Can any used container be shipped as an SOC?

No. The carrier must accept it, and the container must be correctly identified, structurally suitable and supported by valid safety examination information.

Does an SOC avoid every demurrage or storage charge?

No. It may avoid charges for extended use of the carrier’s equipment. Terminal storage, customs examinations and handling charges may still apply.

Who maintains a Shipper’s Own Container?

The owner is responsible for inspection, maintenance, repairs, certification and storage unless a contract clearly transfers a task to another party.

What sizes of SOC containers are available?

Common choices include 20ft and 40ft standard containers, 40ft high cube containers and specialist equipment such as open tops, flat racks and refrigerated containers.