Containers

A container number is the  marking on the door of a container. It is a unique alpha-numeric sequence of four letters and seven numbers to identify containers internationally. 

The fourth character identifies the 'Equipment Identifier' and is usually a U.

It is assigned by the classification agency ISO under their code ISO-6346:1995(E).

Basically a container number looks like:

ABC U 123456 0

Where 'ABC' is the company/owner prefix, the 'U' is the equipment identifier, the 123456 is a sequence or serial number and the 0 is a checkdigit.

• The owner prefix (BIC code): three capital letters of the Latin alphabet to indicate the owner or principal operator of the container,
• The equipment category identifier: one capital letter as follows:
• U for all freight containers,
• J for detachable freight container-related equipment,
• Z for trailers and chassis,
• The serial number: six Arabic numerals, left at owner‘s or operator‘s option,
• The check digit: one Arabic numeral providing a means of validating the recording and transmission accuracies of the owner code and serial number.