ISO 6346
ISO 6346 (2022 edition) is the international standard for coding, identifying and marking containers. A container number consists of a three-letter owner code registered with the BIC, an equipment category letter (U for freight containers, J for detachable equipment, Z for trailers and chassis), a six-digit serial number and a check digit, for example CSQU 305438 3. The standard also defines size-type codes such as 22G1 and 45G1.
Related terms
- Container Check Digit
The check digit is the last digit of an ISO 6346 container number and catches typing errors.
- ISO Size-Type Code
The ISO size-type code is a four-character code on the container door that describes its size and type.
- CSC Safety Approval Plate
The CSC plate is the safety approval plate every container must carry under the 1972 International Convention for Safe Containers (CSC).
Covered in these guides
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 Container sizes & capacity20ft Container Dimensions: Inside, Door Opening and Payload
Inside, door and outside dimensions of a 20ft dry container, its 33.2 m³ capacity, 28,250 kg payload, pallet and carton counts, and common loading mistakes.
6 min read