Container Identification System: what is container marking?

You've probably a bunch of codes and numbers all over the containers and wondered what those are, and what is their purpose.

These container numbers are used to communicate the container’s data in correspondence between the vendor, buyer, transporter, regulatory bodies, and any other parties that may be involved in the transaction. Keep reading to learn what each one of these markings represents.


What is container marking?

Each container includes a variety of marks, such as business names, serial numbers, and codes that show what kind of cargo it can hold and how much weight it is.

Containers must have these required operational markings, which provide all the information required for container movement. Each one of these markings plays an important part in the container's shipping and offers essential information to all parties in the supply chain.

Plus it helps with the tracking of the container and maintaining the container and cargo’s safety during its transportation from the point of pick-up to the point of delivery.


9 Mandatory operational container marking


1- Container number

International cargo is identified by a container number, which is a special alphanumeric combination of seven numbers and four letters.


Container prefix

A code consisting of four Latin letters that enables operators and shippers to identify and track the container and it consists of two codes.

·         Owner code

Three capital Latin alphabet letters are used to identify the owner of the cargo.

·         Product Group

A single capital Latin alphabet letter (U, J, or Z) where U stands for freight containers, J stands for detachable freight container equipment and Z stands for trailers and chassis.


Serial number

The serial number Or the Registration number consists of only 6 digits.


Check digit

The last number on the right is calculated off on the four letters and six digits of the container number. (Owner prefix, equipment’s identifier letters, and the serial number) to check the accuracy and the validation of the container and to identify incorrect container numbers.  It’s always boxed to ensure it stands out from the rest of the number.

and you can calculate the check digit through BIC’s calculator.


2- ISO code

Container Classification (ISO 6346) is a 4-digit code representing the size and type used to identify containers. The first two digits represent the "size code", and the last two digits represent the "type code".

The size code: the first the Length and the second the Width and the Height.

The type code: the third and fourth are for the Features and the Characteristics.


3-  Maximum gross and tare mass

The maximum Gross Weight that they can carry, including their own tare weight, And the Tare weight of the packaging or the container without the goods. The maximum gross weight and tare mass might vary from one container to another.


4- Maximum cargo volume

The maximum cargo volume or the cubic volume is the maximum amount that can fit into the container. Contrary to weight, it is impossible to pack the container too tightly by volume because it will be obvious.


5- Height marks for containers

Containers that are 2.6 meters (8 feet, 6 inches) or taller have a height warning. On the container, there are two spots where height marks are visible. One is underneath the container's identification number, while the other is on the top border of each side.

6- Max. Payload

The net weight is the weight, or mass, of the goods themselves without any packaging. It is the maximum weight of the cargo that can be packed in the is simply the gross minus the tare weight.


7- Owner’s logo

The logo of the owner or the operator of the container. It may be a shipping line or a containing leasing company.


8- Manufacturer’s logo

The logo of the manufacturing company of the container.


9- Container safety certificate (CSC)

Some containers include a container safety certificate (CSC) issued by the manufacturer that must be renewed every 30 months by a certified inspector.



There are many types of containers out there for different types of cargo. Even though there can be slight differences in the measurements of containers from different manufacturers, all containers must meet the ISO standards. Who is in charge of regulating the recognized container standards? In the following article, you will learn more about these containers 6 most common types of containers

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