ISO 6346 is an international standard covering the coding, identification and marking ofintermodal (shipping) containers used within containerized intermodal freight transport. The standard establishes a visual identification system for every container that includes a unique serial number (with check digit), the owner, a country code, a size, type and equipment category as well as any operational marks. The standard is managed by theInternational Container Bureau (BIC).

 

 

 

 

 

 

 

 

 

 

 

 

Owner Code

The owner code consists of three capital letters of the Latin alphabet to indicate the owner or principal operator of the container.

 

Equipment Category Identifier

The equipment category identifier consists of one of the following Four capital letters of the Latin alphabet:

• U for all freight containers

• J for detachable freight container-related equipment

• Z for trailers and chassis

• R for reefer containers (cooling containers, mostly with their own refrigeration system)

 

Serial Number

The serial number consists of 6 numeric digits, assigned by the owner or operator, uniquely identifying the container within that owner/operator's fleet.

 

Check Digit

The check digit consists of one numeric digit providing a means of validating the recording and transmission accuracies of the owner code and serial number.

 

Calculation Step 1

An equivalent numerical value is assigned to each letter of the alphabet, beginning with 10 for the letter A (11 and multiples thereof are omitted):

 

 

 

 

 

 

 

 

 

The individual digits of the serial number keep their numeric value.

 

Calculation Step 2

Each of the numbers calculated in step 1 is multiplied by 2position, where position is the exponent to base 2. Position starts at 0, from left to right.

The following table shows the multiplication factors:

 

 

 

 

 

 

 

 

 

Calculation Step 3

a) Sum up all results of step 2

b) Divide them by 11

c) Erase all decimal digits of the division (i. e. erase everything after the decimal point)

d) Multiply the integer value by 11

e) Subtract result of d) from result of a): This is the check digit!

If the final difference is 10, then the check digit becomes 0. To ensure that this does not happen, the standard recommends that serial numbers should not be used which produce a final difference of 10, however there are containers in the market which do not follow this recommendation, so handling this case has to be included if a check digit calculator is programmed.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Information and photos from Wikipedia.