Glossary · Equipment & tracking
AIS vs carrier EDI data
Also known as Carrier EDI, EDI, and EDIFACT.
One is a ship broadcasting its position, the other is the line reporting what it did to your box. Different questions, and they disagree for good reasons.
Published
AIS is a transponder on a ship broadcasting where that ship is, several times a minute. Carrier EDI is the shipping line sending structured messages about what it did to your container — gate-in, loaded, departed, discharged, gate-out. Both end up on the same tracking page, and they are not the same kind of fact.
EDI stands for electronic data interchange, and in container shipping it usually means an EDIFACT message such as IFTSTA, a status report the line sends to a customer or a platform on a schedule. It is a record of an event, sent after the event.
How they differ, and why it matters
| AIS | Carrier EDI | |
|---|---|---|
| Subject | The vessel | Your container |
| Timing | Continuous while in range | In batches, often hours later |
| Authority | Measured, but by the ship itself | The line reporting its own work |
| Survives transshipment | No | Yes |
| Covers inland legs | No | Usually |
The consequence importers meet most often: the map and the milestones disagree, and neither is broken. The vessel position is current and interpolated between fixes; the milestone is old and true.
A second consequence is quieter. AIS stops being about your cargo the moment the box is lifted off. After a transshipment the ship you were watching is carrying somebody else’s fruit, and only the carrier’s messages still refer to yours.
Which to believe
For where the cargo is and what clock is running, the carrier’s message. Discharge starts free time, and only the line reports it.
For is the voyage progressing, AIS. Carriers publish nothing mid-ocean because there is nothing to publish, so a quiet line plus a moving vessel is a healthy shipment, and a quiet line plus a stationary vessel is a question.
For when will it arrive, neither on its own — see predictive ETA.
Trackberry keeps the two apart rather than blending them: the marker stands on the newest confirmed AIS fix instead of an estimate, and the timeline shows the carrier’s events with the time the line published them.
FAQ
Why does the map show my ship arriving while the carrier says nothing?
Because the two systems report different things at different rates. The vessel feed is continuous and partly interpolated; the line publishes a milestone only when something happens to your container, and mid-ocean nothing does.
Which is more accurate?
Wrong question for most cases — they answer different questions. If you must rank them: the carrier’s event is a record of something that happened, and the vessel position is an estimate of something happening now.
Do I get EDI messages myself?
Large importers sometimes take a direct EDI feed from a line, and it is a project rather than a setting. Most reach the same data through a carrier portal or a tracking platform that holds the connections for them.