Container owner prefixes, explained

The first four letters of a container number say who owns the box. Three letters are the owner code, registered with the Bureau International des Containers (BIC). The fourth is the equipment category.

Anatomy of a container number

Take CSNU 729492 5. Each part has its own job.

CSNOwner code
UCategory: freight container
729492Serial number
5Check digit

The category letter

Equipment category letters
LetterMeans
UFreight container
JDetachable freight-container-related equipment
ZTrailer or chassis

Look up an owner

BIC maintains the official register of owner codes, so that is the place to check who a prefix belongs to. Registration is managed by BIC under ISO 6346.

Search the BIC register