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Containers

Container Check Digit

In Indonesian: Check Digit Nomor Kontainer

The check digit is the last digit of an ISO 6346 container number and catches typing errors. Letters are converted to numbers (A = 10, B = 12 and so on, skipping multiples of 11), each of the ten characters is multiplied by 2 to the power of its position (0–9), and the sum is divided by 11; a remainder of 10 counts as 0. For CSQU 305438 the result is 3. Validate it before submitting shipping instructions, VGM or customs documents.

Related terms

  • ISO 6346

    ISO 6346 (2022 edition) is the international standard for coding, identifying and marking containers.

  • ISO Size-Type Code

    The ISO size-type code is a four-character code on the container door that describes its size and type.

  • Shipping Instruction (SI)

    A shipping instruction is the shipper's instruction to the carrier or forwarder from which the B/L is prepared.

Covered in these guides

Container sizes & capacity

Container Types and ISO Codes: Container Numbers, Check Digits and Type Codes

The main container types (dry, high cube, reefer, open top, flat rack, tank), how to read an ISO 6346 number, calculate the check digit and decode codes like 22G1.

6 min read

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