Container number check
Paste any container number — we validate its check digit with the real ISO 6346 algorithm and decode what each part means.
Enter 4 letters + 7 digits. Spaces and dashes are fine.
How the code works
What do the letters and numbers on a shipping container mean?
The 11-character code (like MSCU 123456 7) is the BIC number: three letters identify the owner, the fourth is the equipment category (U for containers), six digits are the serial, and the last digit is a check digit computed from the first ten characters.
How is the container check digit calculated?
Each letter maps to a number (A=10, skipping multiples of 11), each character is multiplied by 2 raised to its position (0–9), the products are summed, and the sum modulo 11 gives the check digit (10 becomes 0).
How do I track a container by its number?
Track it on the owning carrier's site — the first four letters tell you who that is (MSCU = MSC, MAEU = Maersk, CMAU = CMA CGM, HLXU = Hapag-Lloyd). Universal trackers exist, but the carrier's own tracking is the source they all read from.