Maersk container prefixes

MAEU is registered to Maersk. Take MAEU 136922-2: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 2.

MRKU is registered to Maersk. Take MRKU 655518-6: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 6.

MSKU is registered to Maersk. Take MSKU 675464-1: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 1.

PONU is registered to Maersk. Take PONU 715356-3: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 3.

PONU is the P&O Nedlloyd legacy code, in Maersk hands since the 2005 takeover.

SEAU is registered to Maersk. Take SEAU 156868-4: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 4.

SEAU is Sealand heritage — the code of the company that invented container shipping in 1956, kept alive in the register after Maersk absorbed Sealand.

MNBU is registered to Maersk. Take MNBU 306463-5: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 5.

MNBU is reserved for Maersk’s reefer fleet — spot it and you are almost certainly looking at a refrigerated box.

MRSU is registered to Maersk. Take MRSU 894870-8: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 8.

SUDU is registered to Maersk. Take SUDU 565761-4: each of its first ten characters has a value and a weight, the products are added, and the remainder after dividing by 11 is the check digit — here 4.

SUDU comes from Hamburg Süd, the 150-year-old German line Maersk bought in 2017; the red boxes kept their code.

The tracker at maersk.com accepts the container number inside the link, which we confirmed in a browser: the checker on this page builds that link for you.

Not from the container. A standard dry box has no power, no radio and no satellite receiver — it is a steel case with a number painted on it, and it reports nothing about itself. Every position you see against a Maersk shipment was reported by something else: a terminal crane, a gate reader, or the ship.

A live map on a carrier’s tracking page is almost always plotting AIS, the transponder every large vessel broadcasts with its position, course and speed. That is genuinely useful at sea: it is a real position rather than a schedule, and an ETA recalculated from actual movement. It is also the ship’s position, not your box’s, and the two part company the moment the container is discharged.

On land the map goes quiet. Between the gate-out and the delivery there is no vessel to follow, and the road leg appears only as whatever events the terminal and the trucker report. A container sitting on a chassis in a yard shows the last position of a ship it left days ago. Only specialised IoT equipment reports its own location, and wherever that exists it is a paid product sold to the shipper, not something a tracking page gives away.