What do marks on a container mean?

Compulsory container markings must be used on all containers visible on the door. Each of those markings plays a significant role in transportation and is important relating to the monitoring and safety of the container. Let’s have a look at each of these container markings individually to get an idea what they mean:

(1) The container number is the most important and complex marking on the door and is a sequence made up of for letters and seven numbers. It consists of the

– Owner code (first three capital letters, in this case CBC = Container Brokerage Company) which must be unique and registered with the Bureau International des Containers et du Transport Intermodal (BIC) to avoid duplicates. You can always do a BIC search to identify the owner of a container here.

Equipment category identifier which is “U” for this container and stands for freight containers. Other categories are J – detachable freight containers related equipment and Z – trailers and chassis. Together with the owner code the category can be grouped under one term, known as an alpha prefix.

– The serial number or registration number (200031) consists of six digits.

(2) The last number of the container number is placed out of the rest of the numbers on the right side and is called check digit. It is used to check whether the container number is valid or not. Should the check digit does not correspond to the container number no transport or freight information system can process the container.

(3) According to the International Organization for Standardization, each container is given a unique ISO code in order to avoid problems in naming the container. In our case, 22G1 means it is a 20’ container 8’6’’ high with a tare weight of 2250 kilograms. Click here to see a full ISO code list and see what your containers ISO code stands for. An alpha character in the 4th position of the size-type code indicates a container with reduced strength characteristics.

(4) The container can carry a maximum weight of 30,480 kilograms inclusive its own weight of 2,180 kilograms.

(5) The tare weight of a container is the actual weight of an empty container and 2,180 kilograms in this case. It is given by the manufacturer at the end of manufacturing and labeling and important to consider for every ship operator.

(6) Is the max weight that can be packed (= max. payload) and the difference between (4) Maximum weight and (5) tare weight. In our case you could load the container with 28,300 kilograms of cargo.

(7) Cube – Max. volume that can be packed in cubic capacity and it is of course not possible to over pack the container by volume. The volume is part of the bill of lading and could have financial consequences for the buyers if not correct.

(8) Every container used for international transport needs to have a valid CSC plate to ensure good condition for safety reasons. It contains for instance manufacturing data and information about the equipment owner … we explain everything related to CSC plates for shipping containers in a separate article.

(9) A container has to be operated either under an ACEP or a PES (Periodic Examination Scheme) from day 1. The fist inspections isn’t required until 5 years, but it must have a scheme in place in order to be operated. Without a valid ACEP sticker or Next Examination Date (under the PES), the container should not be loaded onboard a ship.


mandatory additional container markings

Mandatory operational markings that are intended to convey information requested for the movement of containers and to provide visual warnings for the weight of containers, overhead electrical danger and for containers higher than 2,6m.

Most of the container markings are on the front door of a shipping container, but the Identification number (BIC Code + serial number + check digit) and the Size and type code are also displayed on both sides and the front end for the benefit of crane operators, transporters, authorities and fork lift operators.