ISO 6346 is an

international standard international standard is a technical standard developed by one or more international standards organization, standards organizations. International standards are available for consideration and use worldwide. The most prominent such organization ...

covering the coding, identification and marking of intermodal (shipping) containers used within

containerized Containerization is a system of intermodal freight transport using intermodal containers (also called shipping containers and ISO containers). Containerization is also referred as "Container Stuffing" or "Container Loading", which is the pr ...

intermodal freight transport Intermodal freight transport involves the transportation of freight in an intermodal container or vehicle, using multiple modes of transportation (e.g., rail, ship, aircraft, and truck), without any handling of the freight itself when changing ...

by the

International Organization for Standardization The International Organization for Standardization (ISO ) is an international standard development organization composed of representatives from the national standards organizations of member countries. Membership requirements are given in A ...

(ISO). The standard establishes a visual identification system for every container that includes a unique serial number (with

check digit A check digit is a form of redundancy check used for error detection on identification numbers, such as bank account numbers, which are used in an application where they will at least sometimes be input manually. It is analogous to a binary parit ...

), the owner, a country code, a size, type and equipment category as well as any operational marks. The register of container owners is managed by the International Container Bureau (BIC).

Identification system

Example of an ISO 6346 compliant container number: Containernumber

The illustrated example is a code for a container owned by Hapag-Lloyd AG.BIC Codes online
accessed 22 March 2018

Owner code

The owner code consists of three capital letters of the Latin alphabet to indicate the owner or principal operator of the container. Such code needs to be registered at the Bureau International des Conteneurs in Paris to ensure uniqueness worldwide. An owner can apply for more than one code, as normally the first 2 letters are used as the owner code and the third is used to indicate pool (e.g. HLA, HLB, HLX are some Hapag-Lloyd codes to indicate whether container is standard, reefer...)

Equipment category identifier

The equipment category identifier consists of one of the following capital letters of the Latin alphabet: *U for all freight containers *J for detachable freight container-related equipment *Z for trailers and chassis Presently, all official BIC container codes end in "U". However, the

Association of American Railroads The Association of American Railroads (AAR) is an industry trade group representing primarily the major freight Rail transport, railroads of North America (Canada, Mexico and the United States). Amtrak and some regional Commuter rail in North Am ...

recognizes similar codes for their containers and trailers travelling by rail in North America, though these are not recognized by the BIC and lack check digits. Under the ISO code, then, only U, J, and Z are in use. The refrigerated (reefer) container is identified by means of the size type code.

Serial number

The serial number consists of 6 numeric digits, assigned by the owner or operator, uniquely identifying the container within that owner/operator's fleet.

Check digit

The check digit consists of one numeric digit providing a means of validating the recording and transmission accuracy of the owner code and serial number. To compute the check digit, the letters have to be converted to numbers. This is done in three steps:

Calculation step 1

An equivalent numerical value is assigned to each letter of the alphabet, beginning with 10 for the letter A (11 and multiples thereof are omitted): The individual digits of the serial number keep their numeric value.

Calculation step 2

Each of the numbers calculated in step 1 is multiplied by 2^position, where position is the exponent to base 2. Position starts at 0, from left to right. The following table shows the multiplication factors:

Calculation step 3

If the final difference is 10, then the check digit becomes 0. To ensure that this does not happen the standard recommends that serial numbers should not be used which produce a final difference of 10; however, there are containers in the market which do not follow this recommendation, so handling this case has to be included if a check digit calculator is programmed. Notice that step ''(ii)'' to ''(v)'' is a calculation of the remainder found after division of ''(i)'' by 11. Most programming languages have a

modulo operator In computing, the modulo operation returns the remainder or signed remainder of a division, after one number is divided by another (called the '' modulus'' of the operation). Given two positive numbers and , modulo (often abbreviated as ) is t ...

for this. Attention should be paid to how it works in the language chosen; i. e. if it gives back the decimal rest or the integer rest in order to get proper results. 11 is used as divisor because a container number has 11 letters and digits in total. In step 1 the numbers 11, 22 and 33 are left out as they are multiples of the divisor.

Example

Practical problems

In day-to-day business it happens that containers do appear which do not follow the ISO 6346 identification at all; however, they are fully CSC safety approved containers. Usually these are "shippers owned" containers (SOC), which means that they are not owned by the carrier but supplied by the cargo owners (shippers). They may have no registered owner code and no category identifier and have no check digit. It is advisable to follow ISO 6346 as the absence of a compliant identification code causes problems for both carriers and container terminals to correctly identify the equipment and properly deliver the cargo, because computer systems require ISO 6346-conforming naming and as such missing prefixes are invented. For example, YYYY at the carrier and XXXX at the terminal causes the equipment to mismatch. Moreover, since ISO 6346 identification has become a requirement in international Customs conventions (Customs Conventions on Containers and Istanbul Convention), many Customs Administrations have begun validating that containers are marked as per the standard.

Size and type codes

The codes are compiled of the following elements: *First character, representing the length (coded) *Second character, representing the width and height (coded) *Third and fourth character indicating the type of the container The following is an overview of the most common codes: Use the below to calculate size/type of a less commonly used ISO 6346 containers:

Country code (optional)

The country code consists of two capital letters of the Latin alphabet as described in

ISO 3166-1 ISO 3166-1 (''Codes for the representation of names of countries and their subdivisions – Part 1: Country codes'') is a standard defining codes for the names of countries, dependent territories, and special areas of geographical interest. It ...

. It indicates the country where the code is registered not the nationality of the owner or operator of the container. The letters of the code shall not be less than high.

Mandatory operational marks

Operational marks are intended solely to convey information requested for the movement of containers or give visual warnings. They relate to *the weight of containers *a symbol to denote air-surface container *a sign warning of overhead electrical danger *height marks for containers higher than

References

;Notes ;Sources * Bureau International des Containers: Containers BIC-Code (printed brochure)
Container Numbering Guide

External links

Bureau International des Containers (BIC)

Intermodal Check Digit CalculatorBIC Code IdentifierFreight Container Check Digit Calculator
(includes Java source code for download *Static Java Method does not convert "10" check digit to "0")
List of owner codes
(not the official BIC site)
Online check digit calculatorRussian maritime register of shipping - BIC representationContainer numbers validatorGet container dimensions and type by ISO codeCargo container validator ISO 6346 in JavascriptContainer number validation application
- This page fails when container has a Zero Check Digit (as of Feb 6, 2020)
Command line application to generate or validate container numbers.
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