OCEAN FREIGHT VISIBILITY
ETD, ATD, ETA and ATA in Ocean Freight: An Importer’s Milestone Guide
Estimated dates support planning; actual dates confirm events. Importers who separate the two can communicate more accurately, protect warehouse plans and identify delays without treating a schedule as a guarantee.
Ocean freight updates often contain four similar abbreviations: ETD, ATD, ETA and ATA. They describe two events—departure and arrival—and two types of information—estimated and actual. Confusion begins when an estimate is reported as if the event has already happened.
The four milestones at a glance
| Code | Meaning | What it tells the importer |
|---|---|---|
| ETD | Estimated Time of Departure | The vessel or transport leg is currently planned to depart at this time. |
| ATD | Actual Time of Departure | The departure event has occurred according to the reporting source. |
| ETA | Estimated Time of Arrival | The shipment is currently expected to reach the named location at this time. |
| ATA | Actual Time of Arrival | The arrival event has occurred at the named location according to the source. |
ETD: a planning date, not proof of sailing
ETD helps the supplier, forwarder and importer plan cargo readiness, pickup, terminal cutoffs, documentation and customer communication. It may change because of schedule adjustments, port congestion, weather, vessel operations or connection changes.
Before the planned departure, the logistics team should compare ETD with:
- cargo-ready and pickup dates;
- CY open and terminal closing times;
- customs and VGM deadlines;
- Shipping Instructions cutoff;
- booking status and equipment availability.
Maersk’s published guidance explicitly describes ETD as an estimated vessel departure time that remains subject to operational change. That is why “ETD passed” should never be rewritten as “vessel departed” without an actual departure update.
ATD: the event that starts the next control cycle
ATD confirms that the relevant departure event has been recorded. For an ocean shipment, specify whether the ATD refers to the origin port, a transshipment port or another transport leg. One booking may contain several departures.
After origin ATD, an importer should normally:
- confirm the loaded vessel/voyage and actual origin departure;
- review the latest routing and any transshipment connection;
- obtain or approve the bill of lading according to the agreed process;
- update the customer or warehouse with an estimated—not guaranteed—arrival window;
- prepare destination documents, broker instructions and payment/release actions.
For a structured customer update, see our guide on what a post-departure shipment advice should contain. The article is in Chinese but its milestone logic applies to bilingual operations.
ETA: always name the location
An ETA without a location is incomplete. It might mean arrival at the port of discharge, transshipment hub, inland rail ramp, destination warehouse or consignee’s door. These are different operational events.
Ask four questions whenever an ETA is reported:
- ETA where? Port, terminal, ramp, warehouse or final address?
- Based on which source? Carrier schedule, live tracking, terminal data or forwarder estimate?
- Updated when? Record the date and time of the update.
- What still has to happen? Berthing, discharge, customs release, delivery order, appointment or final delivery?
Important distinction
Vessel ETA at the port does not equal cargo availability. The ship may still need to berth and discharge; the terminal must update the container status; carrier, customs and document holds may need release; and delivery arrangements may still be pending.
ATA: arrival has occurred, but the shipment may not be collectable
ATA confirms arrival at a named point. It does not automatically confirm container discharge, customs clearance, carrier release or warehouse delivery. For ocean imports, use separate milestones for vessel arrival, container discharge, availability, customs release, delivery order and gate-out.
This distinction prevents a common communication error: telling the receiving warehouse that cargo has “arrived” when only the vessel ATA is available. If the container is on hold, use the workflow in our ocean container hold triage guide.
How to record milestones in a shipment tracker
Keep planned and actual fields separate. Do not overwrite the original ETD or ETA when the schedule changes; retain the previous value and add the latest update. This creates a useful audit trail.
Minimum tracker fields
- shipment or booking reference;
- location and transport leg;
- original ETD/ETA;
- latest ETD/ETA and update timestamp;
- ATD/ATA when confirmed;
- source link, email or system name;
- variance in days or hours;
- next milestone, action owner and deadline;
- exception reason if known—clearly separated from assumptions.
For a fuller structure, use our ocean freight shipment tracker guide, which covers owners, source dates and exception alerts.
A practical communication format
A useful update distinguishes fact, estimate and action:
- Confirmed event: “ATD Shanghai: 29 October, carrier tracking updated 30 October.”
- Current estimate: “Latest ETA Los Angeles: 12 November; subject to schedule and port operations.”
- Next control point: “We will recheck after transshipment departure / 48 hours before ETA.”
- Importer action: “Broker documents due by 5 November; warehouse appointment not yet confirmed.”
This format avoids false certainty while still giving the customer an actionable plan.
Frequently asked questions
Why did ETA move after the vessel departed?
ETA remains an estimate and may change with vessel speed, weather, port sequence, congestion, berthing availability or transshipment performance. ATD confirms departure; it does not freeze the ETA.
Is ATA the same as cargo delivery?
Only if the named arrival point is the final delivery location. Vessel ATA at the discharge port is not the same as container delivery to the consignee.
Which source should the importer trust?
Use the source closest to the event: carrier data for vessel routing, terminal data for discharge and availability, customs/broker confirmation for clearance, and delivery provider proof for final delivery. Record the source and timestamp rather than combining conflicting updates into one unsupported statement.
Need milestone-based shipment updates?
Vastlog can coordinate bookings, supplier pickup, export milestones and destination handover for shipments from China. We report planned and actual events separately so importers can see what has happened, what remains estimated and who owns the next action.
Information checked on 30 October 2026. References: DHL guide to ETA, ETD, ATD and ATA; Maersk guidance on ETD and ATD. Milestone labels and availability can vary by carrier, mode and tracking platform.
Featured image is representative stock photography and does not depict a Vastlog shipment. Photo: Robert So / Pexels, used under the Pexels License and cropped.
