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Shipping Container ISO Codes

This article is for reference purposes for anyone who needs to find an ISO code for their shipping container, or if you want to understand what this ISO code represents or means.

More and more of our customers are asking for the ISO code for a certain size and type of container, so to help we have included a table below of all the ISO codes for the common types of export grade containers.

All shipping container ISO codes will appear among the information printed on the top right hand of the container doors as you look at them from the outside and they also appear on the top right hand side of the side panels under the container number. (In this example pictures the ISO code is 22G1)

What is an ISO code and what does it do?New build 10 vent shipping container

An ISO code for a shipping container is an internationally recognised means of classifying the container. It allows someone to determine the size and type of a container by looking at the code (bearing in mind when in a stack on board a container boat, looking at the door alone won’t tell you how long the container is, or if it has doors at the other end etc…)

The ISO code is viewable on the top right hand side of all the external panels of a container. On the 20ft container pictured you can see the container number at the top (4 letters followed by 7 numbers) and underneath  is the 4 digit ISO code.

All ISO codes are 4 characters long:

  • The first character signifies the length of the container. 2 = 20ft, 4 = 40ft. There are plenty of other variations but the industry uses circa 95% 20ft or 40ft long containers of one type or another.
  • The second character denotes the height and width of the shipping container.
  • The 3rd and 4th character provide information on the type of shipping container and also any features such as extra doors, whether it’s a ventilated container, has an open top, has open sides, has a removable top, and so on. Further info on this is detailed below.

ISO Codes for popular standard dry / high cube shipping containers

We are often asked what is the ISO code for the shipping container I’ve just purchased. Around 80% of our sales will be one of these 3 types of shipping container, and ISO code is listed next to the container type.

20ft Container 22G1
40ft Container 42G1
40ft High Cube Container 45G1

Please note that these are the most common types of containers. The above 3 ISO codes may also be seen to end in a zero as opposed to a one. The code ending in a 1 signifies that passive vents are used at the upper part of the cargo space. These units with vents (as opposed to containers without passive vents) are much more common on modern shipping containers and can be considered for most purposes to be the case. Any shipping line wanting to know the ISO code typically won’t mind if the container has vents or not, they will be a lot more concerned over the size, shape and state of repair for the container.

You can see a full and detailed list of ISO codes and their assignments on the prefixlist website If you are dealing with a certain type of container and trying to work out what ISO code it should have, we find the Hapag lloyd Container Guide to be a great help if you want to ‘reverse lookup’ an ISO code from a specific size and type of container. This guide is pretty comprehensive. offer the UK’s largest online range of shipping containers for sale with a nationwide network of storage and conversion yards and crane equipped delivery vehicles.

If you need a shipping container feel free to browse our online range of shipping containers for sale, which also includes our ranges of flat pack sheds, container canopies and more. You can also call us on freephone 0808 1234 215 any time 9am – 7pm weekdays and our team will be happy to discuss your requirements. Alternatively, you can use our online shipping container quote form or request a telephone callback. In both cases we aim to get back to you within 1-2 working hours (may take longer for more detailed quotes).

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