What is a BIC code?

A company that owns or operates containers applies to the Bureau International des Containers in Paris, which ISO 6346 names as the registrar of owner codes. The bureau checks that the three letters are not already taken and enters them in its public register. From then on every box the company puts into service is numbered the same way: the three-letter owner code, one category letter (U for freight containers, J for detachable equipment, Z for trailers and chassis), a six-digit serial number of the owner’s choosing and a check digit computed from the other ten characters. The ISO container standards guide explains the rest of the marking.

One company can hold many codes, usually because it has absorbed other fleets over the years; the table above shows the ten largest holders in our curated register. That register lists 85 prefixes belonging to 28 companies — 18 shipping lines and 10 leasing companies — each confirmed against two sources. A further 243 prefixes are recognised from the BIC register alone, and the tool says so when it names one of them.

On the box, the code opens the number stencilled on the upper right of the right-hand door, on both side walls and on the roof. On paper, it opens every container number listed on a bill of lading and on a booking confirmation.

When you have a number in front of you, the code answers one question: whose box is this? Type the full number into the container number checker and it verifies the check digit, names the registered owner of the prefix and points to the right tracker. It does not show where the container is; only the line carrying it can tell you that.

The usual mistake is to read the BIC code as the name of the shipping line. Roughly half of the world’s container fleet belongs to leasing companies, whose boxes sail with whichever line has rented them. A TRLU container belongs to Triton; it may carry Maersk cargo today and MSC cargo next quarter.

The cost is time: people search for a leasing company’s tracking page, and no such page exists, because a lessor never knows what is inside its boxes. For a leased container the operating line is named on your booking confirmation or bill of lading, and its bill of lading number starts with the line’s SCAC. Prefix lists also get owners wrong: TCKU belongs to Triton, not Maersk, and TEMU to Textainer, not Triton.