Can You Track a Shipping Container by Number?
In this article 9 sections
Typing a container number into a ship tracker is one of the most common dead ends in maritime search. If you’ve just pasted an 11-character code like MSCU1234567 or TCNU7654321 into MarineRadar’s search bar hoping to track a shipping container by number the way you’d track a parcel, you got nothing back, and that’s not a bug. A container number was never built to be looked up on a map. Understanding why opens a faster path to the actual ship than most people who hit this wall ever find.
Why a Container Number Returns Nothing on a Ship Tracker
MarineRadar uses AIS (Automatic Identification System) to show where ships are in real time. But there’s one important thing to understand: AIS tracks vessels, not the containers they carry.
AIS works by sharing information about a ship, including its name, MMSI number, position, speed, and direction. It also provides details such as the ship’s IMO number, destination, and estimated time of arrival (ETA). However, it doesn’t tell you what’s inside the ship or which containers are on board.
That’s because AIS was originally developed to help ships avoid collisions at sea. Its purpose is to make vessel movements visible, not to manage cargo information.
So, where does container tracking information come from?
Every shipping container has a unique identification number. Shipping companies use this number in their own tracking systems to record important updates, such as when a container enters a terminal, gets loaded onto a vessel, or reaches its destination port.
These records are stored in shipping carriers’ and terminal operators’ databases, which work separately from AIS.
That’s why entering a container number into MarineRadar won’t give you tracking results. The platform can help you follow the ship transporting your container, but it cannot identify the container using its number alone.
The easiest way to track your container is to enter its number on the shipping carrier’s. Once you know which vessel is carrying it, you can use MarineRadar to follow that ship’s location and movement.
What a Container Number Actually Encodes
Under ISO 6346, every shipping container has a unique 11-character identification code. It includes three letters identifying the owner, a fourth letter showing the equipment type (usually U for freight containers), six serial numbers, and one check digit.
For example, MSCU represents MSC, MAEU represents Maersk, HLXU represents Hapag-Lloyd, and EGHU or EISU represents Evergreen. The check digit helps identify typing errors, while owner codes are officially registered with the Bureau International des Containers (BIC).
The container number is printed in several places, including the doors, side walls, front, and roof, making it easier to identify.
The first three letters help identify the container owner, but the owner may not be the shipping company transporting it. The six-digit serial number identifies the individual container, while tracking updates must be checked through the relevant shipping company’s system
Container Number, Booking Number, Bill of Lading: Not the Same Thing
| Identifier | What it resolves to | When you’d have it |
|---|---|---|
| Container number | One physical box and its custody history | After the box has been loaded, printed on the door and the paperwork |
| Booking number | The whole shipment, before containers are assigned | As soon as you book space with the carrier, often weeks before loading |
| Bill of lading number | The legal contract covering the shipment, sometimes several containers | Once the carrier issues the B/L, usually at or after loading |
Most of the frustration with container tracking comes from using the wrong identifier for the stage you’re actually at. A booking number works for weeks before a container number even exists, and plenty of searches that look like they’ve failed are really just early.
What If the Carrier Hasn't Named a Ship Yet?
A container number is usually assigned before the box goes anywhere near a ship, so an empty or thin result on the carrier’s own page often just means the shipment hasn’t reached that stage yet. The normal sequence runs from empty release, where the box has been allocated but is still sitting at a depot, through gate in, where it enters the terminal and a vessel may be provisionally assigned. Loaded on board comes next, and that’s the first point a ship name actually exists to search for.
Transhipment complicates this further. On a two-leg route the box changes ships at a hub port such as Singapore, Algeciras or Jebel Ali.
The carrier’s tracking page sometimes keeps displaying the first vessel for a day or two after the box has already moved to the second. If a ship you’ve been watching suddenly stops matching the timeline the carrier shows, re-check the carrier page before assuming the live tracker is wrong. It almost always means the box has changed hands, not that the AIS data has gone stale.
The Actual Path From a Container Number to a Live Ship Position
This is the part a container number alone can’t do, but a container number plus two extra lookups can, and the whole thing takes a few minutes the first time.
Step 1: Confirm you actually have a container number
Count the characters. Four letters followed by seven digits, eleven in total. A nine-digit code or something with a mix of letters scattered through it is a booking reference or a bill of lading number, not a container number, and it belongs on a different part of the carrier’s site entirely.
Step 2: Read the owner prefix
The first four characters tell you who to ask. MAEU is Maersk, MSCU is MSC, COSU is COSCO, HLXU is Hapag-Lloyd, OOLU is OOCL, EGHU and EISU are Evergreen. If the prefix belongs to a leasing company instead, the carrier’s own site still accepts the number, since the carrier actually moving the box is what matters for tracking, not who owns the steel.
Step 3: Go to that carrier’s own tracking page
Every major carrier runs a free container tracking tool that takes the number and returns the custody history: booked, gated in, loaded, in transit, discharged, delivered. MarineRadar’s own HMM container tracking guide and Evergreen container tracking guide walk through two of these in detail, including the exact fields each one shows and how to read a carrier that still uses the old Hyundai Merchant Marine prefix.
Step 4: Write down the vessel name and voyage number
Somewhere in that custody history, usually next to the loading event, the carrier names the ship and a voyage code such as 047E. That’s the piece a container number can’t give you directly, and it’s the only piece you still need before the rest of this is just typing a name into a search box.
Step 5: Open a live ship tracker for that vessel
Search the vessel name on MarineRadar and you get its position updated from AIS, typically within the last few minutes near a coast and somewhat longer mid-ocean, plus course, speed and the port it’s currently heading toward. This is the half the carrier page was never built to show.
Step 6: Compare the carrier’s ETA to the ship’s actual course and speed
A carrier’s quoted ETA is usually set at booking and rarely revised until the box is discharged. A live AIS position moves constantly. If the ship has slowed well below its usual service speed or is sitting off a port at single-digit knots, that shows up on the live map days before the carrier’s static ETA catches up to reality.
Carrier Tracking Pages Only Go So Far
A carrier tracking page is a system of record, and systems of record log what already happened. They tell you a box was loaded three days ago, discharged yesterday, or gated out this morning. They do not tell you where the ship is tonight, because recording custody checkpoints was never the job they were built for, and a carrier updating that page in near real time would gain almost nothing for the cost of building it. That gap between the last logged event and right now is exactly what sends people searching a container number on a map in the first place, and it’s a reasonable thing to want. It’s just the wrong tool for it, the same way checking a delivery company’s warehouse scan log won’t tell you which street the van is currently on.
Third-Party 'Universal' Container Trackers
A handful of sites advertise tracking any container number from any carrier in one box. In practice these work by detecting the owner prefix and querying that carrier’s own tracking API behind the scenes, then presenting the result in their own layout rather than the carrier’s. They inherit the same limit as the carrier page itself: a custody log, not a live position, because they’re reading from the same source. Some add an AIS feed on top for the resolved vessel, which is the same two-step path described above, just stitched together automatically instead of by hand. That automation is convenient when you’re tracking a dozen boxes across different carriers at once; it isn’t doing anything a container number plus a ship name couldn’t already get you for free.
Once You Have the Ship, What Live AIS Tracking Adds
Knowing the vessel name changes what you can watch. A live tracker shows current position, heading and speed, refreshed as new AIS messages come in rather than at fixed carrier-logged checkpoints, which means a slowdown or a port queue building up shows on the map well before the carrier’s static page catches up.
Coverage isn’t uniform. Dense coastal networks near ports report every few seconds, while a ship mid-ocean relying on satellite AIS reports less often, so a longer gap between updates out at sea is normal rather than a sign something’s wrong.
For the underlying technology, MarineRadar’s guide to what an AIS transponder actually broadcasts covers exactly which fields come from the ship itself. If a vessel name search doesn’t surface the right ship, searching its MMSI number instead resolves the ambiguity, since MMSI is unique where ship names sometimes repeat across a carrier’s fleet.
A Quick Owner-Prefix Reference
| Prefix | Usually assigned to |
|---|---|
| MAEU, MRKU | Maersk |
| MSCU, MEDU | MSC |
| COSU, CBHU | COSCO |
| HLXU, HLCU | Hapag-Lloyd |
| OOLU | OOCL |
| EGHU, EISU, EGSU | Evergreen |
| HMMU | HMM (current) |
| HDMU | HMM (pre-2020 rebrand, still circulating) |
| TCNU, TGHU, TRHU | Leasing companies, not a shipping line |
None of these prefixes resolve on a live ship tracker directly. Each one points to a carrier’s own tracking page first, and from there to identifying the vessel by name or MMSI once the carrier has given you one. A leasing prefix on the last three rows is the one case worth a second look, since it names who owns the box rather than who’s sailing it, and the carrier’s own documentation is still the one that tells you which.
Conclusion
A container number is a precise, well-designed identifier for exactly one thing: telling a carrier’s own system which box you mean. It was never meant to resolve to a point on a map, and no amount of searching a ship tracker will make it do that. The two-step route, carrier page for the vessel name, live tracker for where that vessel actually is right now, gets you further than either tool manages alone, and it takes under a minute once you know the order to do it in.
MarineRadar is free to start on Android and iPhone. Once a carrier’s tracking page hands you a vessel name, it’s on screen within seconds.
FAQs
Can you track a container by its number?
Not directly, no. A container number resolves on the carrier’s own tracking page.
How do I track a shipping container by number?
Enter it on the carrier’s own tracking page first, the one matching the four-letter owner prefix. That page returns the loading event and the vessel name. Search that vessel name on a live ship tracker such as MarineRadar to see its current position, speed and course, none of which the carrier page shows you, since the carrier’s job stops at logging custody checkpoints rather than watching the open ocean.
Is there a free way to track a container by number?
Yes. Every major carrier’s container tracking page is free, and so is tracking the resulting vessel on MarineRadar.
What is a container tracking number?
It’s the 11-character code printed on the container door and the shipping documents under ISO 6346: a three-letter owner code, a fourth letter for equipment category, six serial digits, and a check digit that validates the rest.
Can AIS track a container?
No. AIS broadcasts a ship’s identity and position, not its cargo.
Why does my container number show no results when I search it on MarineRadar?
Because MarineRadar searches ships, identified by name, MMSI or IMO number, not cargo. A container number has no AIS equivalent to match against, which is why the search comes back empty rather than returning a wrong result. Get the vessel name from the carrier’s own tracking page first and that same search box will find it immediately.
How accurate is the ETA a carrier gives for my container?
It’s usually set at booking and updated infrequently, so treat it as a rough plan rather than a forecast. A live ship tracker reflects the vessel’s actual current speed and course, which moves the real arrival estimate well before the carrier’s own page is revised.
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