CAI container tracking

How to read a CAI container number

ATKJ1155391 example only — not a real shipment

Container numbers follow ISO 6346, the international standard for freight-container identification: four letters, six serial digits, then one check digit. The first three letters are the owner code — registered with the BIC (Bureau International des Containers) — and the fourth letter is the equipment category (U for a standard freight container).

Take ATKJ1155391 as a CAI-style example: ATKJ is the registered prefix (owner code ATK plus the category letter J), 115539 is the serial, and the final 1 is the check digit computed from the ten characters before it — tracking systems use it to catch typos before they search.

If your CAI tracking isn’t working

1. 1 Check the number format first

   Container numbers are exactly four letters plus seven digits (like ATKJ1155391). A common slip is confusing the letter O with zero, or dropping the final check digit. Copy the number from the door of the container or your booking confirmation rather than retyping it.

2. 2 Make sure the number was issued by this carrier

   If your shipment was booked through a freight forwarder, the number on your paperwork may be the forwarder’s own reference, which CAI’s system won’t recognise. Ask whoever issued your documents which carrier number to use — or paste the number on our homepage and we’ll work out who it belongs to.

3. 3 Too early or too late

   New shipments can take a little while to appear — most carriers only start returning results once the container is in their system after export gate-in or acceptance. Long-delivered shipments drop out too: tracking data is usually purged weeks or months after delivery.

4. 4 Paste carefully on CAI’s page

   CAI asks you to type the number on its own page, so paste it exactly — no spaces before or after, and no extra characters picked up from an email. If the page shows a security check, complete it and search again.

5. 5 Still nothing?

   Your booking agent or CAI’s customer service can look the shipment up internally — have the container number and the issuing office or booking reference handy when you ask.

Frequently asked questions

How do I track a CAI container?

Type your container number in the box above and press Track. You’ll land on CAI’s own tracking page — paste your number there and search. CAI container numbers usually begin with ATKJ, ATKU, ATKZ, BEAJ.

What does a CAI container number look like?

Container numbers follow the ISO 6346 standard: four letters then seven digits (for example CSNU1234567). The first four letters identify the owner. For CAI the owner prefixes are typically one of ATKJ, ATKU, ATKZ, BEAJ, BEAU, BEAZ. A format-valid example is ATKJ1155391.

Why does the CAI page open without my number filled in?

CAI asks everyone to enter the number on its own page (it has a security check), so it can’t be filled in ahead of time. We bring you to the right page — just paste your number there.

What if my number doesn’t start with ATKJ or ATKU?

Then it probably wasn’t issued by CAI — shipments booked through a freight forwarder or partner carrier often travel under another company’s container number. Paste the number on our homepage and we’ll suggest the right shipping line, or check your shipping paperwork for who issued it.

Is this CAI’s official tracking site?

No — this is a free, independent tool that brings every carrier’s tracking together in one place. When you track here you end up on CAI’s own page, so everything you see comes straight from CAI. We never see or store your shipment details.