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Container prefixes: reading the owner code on any container

Three letters that tell you whose container it is, and why that is not always whose ship it is on.

Aron Mayer · 4 min read

Quick take

  • Owner codes are registered internationally and are unique.
  • Carrier owned containers carry the carrier prefix, and that is the easy case.
  • Leasing company prefixes tell you nothing about the routing.

The owner code is the most immediately useful part of a container number, because it is the part you can read at a glance.

How the registry works

Owner codes are three letters, registered with the international container bureau, and unique to one owner. The fourth letter is the category, almost always U for freight containers. Registration means no two owners share a code, which is what makes prefix lookup reliable.

Carrier prefixes you will meet

PrefixOwner
MSCU, MEDUMSC
MAEU, MRKU, MSKUMaersk
CMAU, CGMUCMA CGM
HLCU, HLXUHapag-Lloyd
COSUCOSCO
OOLUOOCL
ONEUOcean Network Express
EGHU, EISU, EGSUEvergreen

Large carriers hold many codes, accumulated through fleet growth and acquisitions, so this is a sample rather than a list.

See it on your own shipment

Paste a container number, bill of lading or booking reference. We detect the carrier across 170+ shipping lines, and when the data does not line up, a person checks it.

Leasing prefixes

Codes belonging to leasing companies such as Triton, Textainer or Seaco identify the owner of the steel, not the operator of the voyage. A leased container can be on any line. When you see a lessor prefix, stop trying to infer the carrier and ask for the bill of lading instead.

Questions people ask

Can a carrier have more than one prefix?

Yes, several. Large lines register many owner codes over time.

Does the prefix change when a container is sold?

The physical marking is repainted. Until then, records and marking can disagree.

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