Shipper Owned Containers for Export Shipping

What is a shipper-owned container?

An SOC travels on a shipping line's vessel, but it does not form part of the carrier’s owned or leased container fleet. The shipper books space for the container and remains responsible for its condition, identification, examination status and onward use.

A carrier-owned container, commonly shortened to COC, belongs to or is leased by the shipping line. The carrier supplies the unit for shipment and normally requires the consignee to empty it and return it within an agreed-upon free period.

Businesses often choose SOC equipment when cargo will remain inside at the destination, when a remote project cannot unload immediately or when the empty unit will become secure site storage. An SOC can reduce exposure to carrier equipment detention, but it does not automatically remove port storage, terminal handling, customs examination or transport waiting charges.

Calculating the cost exposure created by delays

Demurrage usually refers to a container remaining at a port or terminal beyond the allowed period. Detention usually relates to a carrier-owned container remaining outside the terminal beyond the agreed return period. Contract wording varies, so the booking confirmation and carrier tariff must control the calculation.

The basic calculation is:

Chargeable delay days = actual equipment days minus allowed free days.

Delay exposure = chargeable days multiplied by the applicable daily charge.

For example, a project that requires 20 days before unloading, after a 7-day free period, results in 13 chargeable equipment days when a carrier-owned container is used. An SOC may remove that carrier equipment element because the shipper owns the box. Terminal storage can still accrue if the container remains inside the port.

A proper comparison should include anticipated terminal dwell, destination unloading time, empty return transport, SOC acceptance charges, inspection requirements and repositioning after discharge. Obtain each charge in writing because carriers may use different free periods and stepped charging bands.

Choosing suitable SOC equipment

The container must suit the cargo, route, lifting method and destination facilities. General cargo commonly travels in a dry freight container with cargo doors at one end.

• 20ft standard containers suit dense cargo, tools, machinery and boxed goods.
• 40ft standard containers provide additional internal capacity for bulky loads and palletised products.
• 20ft open top containers allow crane loading through a removable roof opening.
• 40ft flat rack containers support machinery and oversized cargo that cannot fit inside enclosed walls.

Check container sizes, weights, door openings and payloads before ordering. Payload means the maximum cargo weight permitted within the container’s approved gross weight. Tare means the weight of the empty container. The detailed 20ft standard container dimensions help loading teams confirm internal clearance and door access.

CSC plate and container safety responsibilities

A CSC plate is the safety approval plate fitted to a freight container under the International Convention for Safe Containers. The plate records approval information, including the approved gross weight and examination details.

The International Maritime Organization’s CSC information explains that the Convention establishes structural safety requirements, testing procedures and an examination system for containers used in international transport.

Under the CSC framework, the owner remains responsible for maintaining the container in safe condition and arranging examinations under an accepted periodic examination scheme or an approved continuous examination programme. A visible plate does not make damaged equipment acceptable. The owner must still check the understructure, corner posts, roof, side panels, doors, flooring, locking gear and lifting points.

Shipping lines may request photographs, inspection records, evidence of ownership, or examination details before accepting an SOC. The carrier can reject equipment that does not meet its operational requirements even when a plate remains attached.

Verified gross mass requirements

Verified gross mass, shortened to VGM, is the confirmed total mass of a packed container, including its cargo, packing materials, securing materials and tare.

The IMO guidance on verified gross mass states that the shipper named on the bill of lading must provide the VGM to the vessel master or representative and the terminal representative sufficiently in advance of loading. A packed container must not be loaded onto a vessel when the required VGM has not been provided.

The IMO permits two methods:

1. Weigh the complete packed and sealed container using calibrated and certified equipment.
2. Weigh the cargo items, packages, pallets, packing and securing materials, then add the container tare using a method accepted by the relevant national authority.

The VGM declaration should identify the container, state the verified mass and carry the name of the person authorised by the shipper. Carrier portals, terminal systems, and freight forwarder procedures may impose submission deadlines before vessel arrival.

BIFA provides supplementary operational materials through its freight-forwarding information and guidance resources. Carrier instructions and official IMO requirements take priority where procedures differ.

Step-by-step export documentation process

1. Confirm the exporter and obtain an EORI number. A business moving goods between Great Britain and another country will normally need an Economic Operators Registration and Identification number. Check the current GOV.UK EORI guidance.
2. Classify the goods. Select the correct commodity code through the UK Integrated Online Tariff. The code affects declaration data, duty treatment, restrictions and statistical reporting.
3. Check export controls and destination restrictions. Confirm whether the goods need an export licence, certification or additional approval. Controlled goods can include military items, dual-use products, cultural goods, chemicals, plants and certain food products.
4. Prepare the commercial documents. Produce a commercial invoice containing the seller, buyer, goods description, quantity, value, currency, delivery terms and country of origin. Prepare a packing list showing packages, weights, dimensions and marks.
5. Obtain SOC acceptance. Give the carrier the container number, type, dimensions, examination details and any inspection evidence it requests. Confirm the booking as SOC equipment before transport to the port.
6. Submit the export declaration. The exporter or appointed customs agent submits the required declaration through the Customs Declaration Service. Follow the current GOV.UK export declaration guidance.
7. Record the declaration reference. Keep the Movement Reference Number and provide it to the haulier, the port community system, or the carrier when required. Ensure the declared container number matches the physical unit.
8. Submit the VGM. Calculate the verified gross mass using an accepted method and transmit it before the carrier’s deadline.
9. Complete port presentation and customs clearance. Follow the port's arrival procedure and respond to any customs inspection or document request. GOV.UK provides an overview of the process for businesses that export goods from the UK.
10. Retain the shipment records. Keep the invoice, packing list, declaration data, transport document, VGM evidence, licences, inspection records and proof of export in line with current HMRC requirements.

Delivery, access and siting

Delivery planning must account for road width, overhead cables, trees, gates, gradients, ground strength and vehicle operating space. Use the container delivery and siting guide before arranging collection or loading.

A firm, level base should support the corner castings and allow the cargo doors to operate properly. Planning requirements depend on location, use and duration, so check the national Planning Portal guidance and contact the relevant local authority where necessary.