How Maersk Container Tracking Actually Works: What the Portal Shows, What It Doesn't, and What the Events Mean

Key Takeaways

The portal shows up to nine milestones from pre-booking through delivery, but empty return is not included as a distinct public milestone.
Maersk’s public tracking at maersk.com/tracking requires no login and accepts container numbers, B/L numbers, booking references, and parcel tracking numbers.
Maersk has the most accessible developer portal among major carriers — developer.maersk.com offers genuine self-service registration with a sandbox environment.
Hamburg Sud and Sealand are fully integrated. SUDU and SEAU container prefixes are trackable on maersk.com. The hamburgsud.com domain redirects to Maersk.
Schedule reliability is the highest of any carrier — 76.7% in December 2025, well above the industry average which sat at roughly 64% in late 2025.
The Gemini Cooperation with Hapag-Lloyd launched February 1, 2025, with ~340 vessels across 57 services in a hub-and-spoke model.
Inland tracking gaps persist when third-party truckers handle the drayage leg. Maersk’s portal loses visibility once the container leaves carrier-controlled infrastructure.

Schedule reliability figures, update cadence estimates, and carrier performance data referenced in this guide are based on third-party industry reports and may reflect specific monthly snapshots rather than sustained averages. Carrier systems and capabilities are subject to change.

What the Portal Shows You

Maersk has more tracking interfaces than any other carrier. The public portal at maersk.com/tracking is the starting point — no account needed. Beyond that, Maersk offers the Maersk App (mobile), Maersk Flow (digital freight platform for BCOs), and Maersk Go (online booking tool). Each surface pulls from the same underlying data, but the feature set differs.

The public tracker accepts four identifier types: container number, bill of lading number, booking reference, and parcel tracking number. The parcel tracking option reflects Maersk’s push into end-to-end logistics beyond ocean freight. For pure ocean tracking, container number or B/L will give you the most complete milestone timeline.

Container prefix coverage is broad. Maersk’s SCAC is MAEU, but the most common container prefix you will encounter is MSKU. The fleet also includes MRKU, MRSU, SEAU (legacy Sealand), and SUDU (legacy Hamburg Sud). All are trackable through the same portal. Hamburg Sud’s website now redirects to maersk.com, and all historical SUDU/SEAU bookings are accessible there. For guidance on which identifier to use when, see our identifier guide.

What you will not find on the public portal: bulk tracking (you cannot paste a list of container numbers), predictive alerting, or document access. For those features, you need a Maersk account and access to Maersk Flow or the API.

Event Names and What They Mean

Maersk publishes up to nine milestones per shipment, from pre-booking through delivery. The event labels differ from other carriers — what MSC calls “Loaded (at POL),” Maersk calls “Loaded on Vessel.” The table below maps each Maersk label to its meaning and the DCSA standard code.

Maersk Event Label	What Actually Happened	DCSA Code
Pending Vessel	Container is booked but not yet assigned to a confirmed vessel	—
Gate In (Full)	Laden container entered the origin terminal	GTIN
Loaded on Vessel	Container was lifted onto the vessel at port of loading	LOAD
Departure from POL	Vessel left the port of loading	DEPA
Arrival at POD	Vessel arrived at the destination port	ARRI
Discharged at POD	Container was unloaded from the vessel at destination	DISC
Gate Out (Full)	Container left the destination terminal (picked up by trucker)	GTOT
Delivery Has Been Completed	Container delivered to the consignee’s location	DLVD

“Pending Vessel” is a planning state, not a physical event. It means Maersk has accepted the booking but the container has not yet been assigned to a specific sailing. This label can persist for days on bookings made well in advance. It does not mean something has gone wrong — it means Maersk has not yet finalized the vessel allocation.

Empty return does not appear as a distinct milestone on the public tracking timeline. After “Gate Out (Full)” or “Delivery Has Been Completed,” the tracking effectively ends. If you need confirmation that the empty container was returned to the depot within the free time window, you will need the terminal’s records or the Equipment Interchange Receipt (EIR), not Maersk’s portal.

Transshipment events are condensed. If a container moves through a transshipment port, Maersk typically shows arrival and departure at the hub, but the detail is thinner than what you see on carriers like ZIM. If you track across multiple carriers and notice that the same transshipment port appears differently, our event naming comparison maps these differences.

Update Cadence: How Fresh Is the Data?

Maersk’s tracking is event-driven. Updates post when terminal milestones fire — gate-in, vessel load, discharge — rather than on a fixed polling schedule. The physical-to-digital lag is comparable to other top-tier carriers: typically 2-8 hours for ocean milestones, though it can stretch longer for events at congested ports or during transshipment.

The Gemini Cooperation adds a wrinkle. Since February 2025, Maersk and Hapag-Lloyd operate a joint hub-and-spoke network with ~340 vessels across 57 services. When a Maersk-booked container moves on a Hapag-Lloyd-operated vessel (or vice versa), the tracking data flows through an alliance data-sharing layer. In most cases this is transparent to the shipper, but the lag can be slightly longer on alliance-operated legs than on Maersk’s own vessels.

Silence between departure and arrival is normal. On a direct transpacific service, you will see “Departure from POL” and then nothing until “Arrival at POD” two to three weeks later. No mid-ocean updates, no position pings. Our guide on why tracking stops updating explains what causes these gaps and when they signal a real problem.

Known Gaps and Quirks

No predictive alerting on the native portal. Maersk’s public tracking shows what has already happened. It does not proactively notify you that a vessel is running behind schedule, that an ETA has shifted, or that a container is at risk of missing its connection. You find out when the event fires — or does not fire when you expected it to.

Inland visibility drops off with third-party truckers. Maersk’s tracking covers the ocean leg and carrier-controlled terminal operations. Once a container is picked up by a third-party drayage provider (merchant haulage), Maersk loses visibility. The “Gate Out (Full)” event fires when the container exits the terminal, but the “Delivery Has Been Completed” event depends on the trucker reporting back — which many do not. If you are using merchant haulage, expect the tracking timeline to end at “Gate Out.”

No bulk tracking on the public portal. You cannot paste a list of 50 container numbers and get results. Each lookup is one container at a time. For bulk visibility, you need the API or Maersk Flow.

No public vessel map. Unlike some carriers that embed a live vessel position map in their tracking results, Maersk does not offer this on the public portal. If you need to know where a vessel is mid-ocean, you will need a third-party AIS service like MarineTraffic or VesselFinder.

OneWireless IoT is rolling out but not yet complete. Maersk is deploying 4G/LTE connectivity across its approximately 450 vessels under the OneWireless program, with a Q1 2026 target. This will enable more granular, near-real-time data from the vessel level — but as of early 2026, the rollout is still in progress and the data is not yet surfaced in the public tracking portal.

Hamburg Sud legacy bookings can be confusing. While all Hamburg Sud tracking now lives on maersk.com, some older booking references and historical data may not map cleanly to the Maersk interface. If you are looking for a pre-2024 Hamburg Sud shipment and the Maersk portal returns no results, try searching by the SUDU or SEAU container number instead of the booking reference.

What to Do When Tracking Breaks

Scenario 1: “Pending Vessel” persists for more than a week. This usually means the booking has not yet been confirmed against a specific sailing. Check whether Maersk has sent a booking confirmation with a vessel name and voyage number. If not, contact your Maersk booking contact — the container may have been rolled or the booking may still be in queue for vessel allocation.

Scenario 2: No update after “Gate In (Full)” for several days. The container has entered the terminal but no “Loaded on Vessel” event has fired. This can mean the vessel has not yet arrived at port, or the container has been loaded but the event has not yet synced. Check the vessel schedule for the confirmed sailing date. If the vessel has already departed and the container still shows “Gate In,” contact Maersk — the container may have been rolled to the next sailing.

Scenario 3: Tracking ends at “Gate Out (Full)” with no delivery confirmation. If you are using merchant haulage, this is expected. Maersk loses visibility once a third-party trucker picks up the container. The “Delivery Has Been Completed” event depends on data flowing back from the drayage provider, which often does not happen. Track the drayage leg through your trucker directly.

Scenario 4: Hamburg Sud container returns no results. Try searching by the container number (SUDU or SEAU prefix) rather than the booking reference. Legacy Hamburg Sud booking numbers may not resolve correctly on the Maersk platform, but container-level lookups should work.

Scenario 5: ETA shifted significantly after transshipment. Under the Gemini Cooperation’s hub-and-spoke model, transshipment connections depend on feeder vessel scheduling. If a container misses its planned feeder, the ETA can shift by days. Check whether a new vessel name appears in the tracking timeline. If not, contact Maersk for the revised connection details.

API and Integration Options

Maersk has the most developer-friendly API among the major carriers. The developer portal at developer.maersk.com offers genuine self-service: a five-step registration process, API key generation, a sandbox environment for testing, and detailed documentation. No sales rep required.

Two primary tracking APIs are available: Track and Trace Plus (detailed milestone history for a container or B/L) and MEC Tracking (event-level data for Maersk, Hamburg Sud, and Sealand containers). Both follow DCSA Track and Trace v2.2 in production.

What the API adds over the portal: bulk lookups, webhook-style push notifications, programmatic access to event timestamps and vessel details, and the ability to integrate tracking data directly into your TMS or visibility platform. If you are managing more than a handful of Maersk shipments, the API is a meaningful upgrade over manual portal checks.

DCSA alignment is strong. Maersk is a DCSA founding member, and its API output maps cleanly to the DCSA event model. If you are building a multi-carrier integration, Maersk’s data is among the easiest to normalize alongside Hapag-Lloyd, CMA CGM, and ONE.

Operational Note: Maersk’s tracking data is among the most reliable in the industry, but “most reliable” still means roughly 1 in 4 arrivals deviates from the original ETA. The Gemini Cooperation with Hapag-Lloyd has pushed schedule reliability above 90% on alliance services, but the hub-and-spoke model introduces transshipment risk that the old point-to-point 2M network did not have. If your shipment routes through a Gemini hub, monitor the feeder connection — that is where delays are most likely to compound. For teams managing multi-carrier operations that need shipment-level visibility beyond what the carrier portal provides, normalizing Maersk’s DCSA-aligned data with other carrier feeds is the most straightforward integration path available.