Container Numbers

Container Numbers

What is a Container Number?

A container number is a distinctive alpha-numeric code comprising seven digits and four letters, used for international container identification. The International Standards Organization (ISO), facilitated by the Bureau International des Containers (BIC), allocates these unique codes to each container, following the guidelines outlined in the ISO 6346 standard.

These codes play a pivotal role in conveying essential details concerning the cargo, transportation, ownership, and condition of the shipping container

What is the Container Number Format?

There are five components that make up the container number, as explained in the following table.

Owner Prefix CodeThe first three capital letters of the container number identify the container owner. They must be unique and registered with the BIC. For example, “MAE” is the code for Maersk.
Equipment CategoryThe letter following the owner prefix code indicating the category of the container. “U” is for freight containers, “J” is for detachable freight container-related equipment, and “Z” is for trailers and chassis. A freight container from Maersk would be “MAEU.” 
Serial NumberA six-digit number determined by the container owner that is a unique identifier for the container.
Check DigitThe last number of the container number, placed separately for validation purposes. It is always boxed, so it stands out from the other numbers.
ISO CodeA sequence of four letters or digits usually located below the container number that provides information about container type and dimensions. For example, ISO code 45G1 means the container is a 45-ft high cube general-purpose container.
Container Numbers

What Role Do Container Numbers Play in Maritime Shipping?

Container numbers serve as unique identifiers for shipping containers. Here are some key roles they play:

  • Identification: uniquely identifies each shipping container, allowing stakeholders such as shipping lines, port authorities, and customs officials to track and manage containers throughout the logistics chain
  • Documentation: essential for documentation purposes, including bill of lading, customs declarations, and inventory records, as they ensure accurate and efficient documentation, reducing administrative errors and delays
  • Security: enables authorities to monitor the movement of containers and detect any unauthorized or suspicious activities
  • Efficiency: streamlines processes, such as container handling, storage, and inventory management

Customers also use container numbers to track their goods as they move through the supply chain. Once the customer receives their container number, they should be able to access the tracking system of their shipping provider. Once they enter the container number into the platform, the system displays the container’s current location, status, and estimated delivery date. 

What Do the Other Numbers and Markings Mean on a Container?

The outside of a container also includes mandatory operational markings. These markings appear on both sides of the container to ensure that they are visible to crane operators, authorities, and other transporters:

  • Gross weight: the total maximum weight of a loaded container, including the weight of the container.
  • Tare weight: the total weight of an empty container.
  • Net weight: the maximum weight that can be loaded into the container. It is the gross weight minus the tare weight.
  • CU. cap.:  the maximum volume of cargo that can be loaded into a container.

Weights are typically presented in both pounds and kilograms, due to the international nature of maritime shipping. Cu. Cap. is presented in cubic meters and feet. 

How Does Container Tracking Work? 

Advanced container tracking using Maritime AI™ technology leverages AI and machine learning algorithms that collect and analyze vast amounts of data from various sources. These include satellite imagery, weather patterns, and port data, to provide real-time visibility into container movements. This generates the most accurate estimated time of arrival (ETA) predictions for the entire global fleet of container vessels.

Container tracking via the booking reference number, can ensure you receive container insights early. Shippers and freight forwarders are usually given a booking reference number when booking a container. Tracking the container before it is loaded onto a vessel can provide valuable information about any issues with vessel changes, and changes in location.

What are the Advantages of Automated Ocean Container Tracking?

Automated ocean container tracking offers numerous advantages:

  • Real-time visibility: easily monitor container locations, crucial for transshipments across multiple ports
  • Improved supply chain efficiency: gain actionable insights for better inventory management and smoother operations, identifying and mitigating bottlenecks
  • Exception management: automated notifications streamline tracking, saving time on manual tasks and enabling focus on critical shipments
  • Cost reduction: optimize routes, avoid port congestion, and minimize detention and demurrage charges with accurate ETA predictions from Maritime AI™ technology