Container number checker
Check the last digit of a container number or calculate a missing one.
Free to use. No account needed.
How it works
Enter the three-letter owner prefix, equipment category U, J or Z, and six serial digits. ISO 6346 assigns numbers to letters, weights each character by a power of two, and uses the remainder modulo 11. A remainder of 10 becomes zero.
A matching check digit detects some transcription errors. It does not confirm registration, ownership, location or the physical condition of a container.