---
title: "Container type code"
description: "Two digits  the first of which indicates the category and the second of which indicates certain physical characteristics or other attributes. also container Siz"
url: "https://oceancargo.co.uk/shipping-terms/container-type-code"
date: "2026-04-15T21:55:58+00:00"
language: "en-GB"
---

![Ocean Cargo](https://oceancargo.co.uk/images/GenPics/OCs-Customs-Brokerage.webp)

 # Understanding Container Type Codes and ISO 6346 for Global Freight

## Demystifying Container Codes: Your Guide to Efficient Shipping

In the intricate world of global logistics, precision is paramount. Every detail, from the cargo itself to the vessel it travels on, is meticulously categorised to ensure seamless movement across borders. For businesses engaged in international trade, understanding the nuances of container identification is not just helpful – it's essential for optimising supply chains, ensuring compliance, and avoiding costly delays. At Ocean Cargo, we believe in empowering our clients with knowledge, and a fundamental aspect of this is deciphering the universal language of container codes.

This comprehensive guide will delve into the critical standards that govern container identification: the Container Type Code and the ISO 6346 standard. These codes, though seemingly small, carry a wealth of information about a container's physical characteristics, capacity, and suitability for various types of cargo. Mastering them will enable you to make informed decisions, communicate effectively with freight forwarders, and ultimately, streamline your shipping operations. Let Ocean Cargo be your trusted partner in navigating these complexities, ensuring your goods are always in the right container for their journey.

## The Foundation: What is a Container Type Code?

The Container Type Code is a two-digit alphanumeric identifier that provides a quick snapshot of a container's fundamental characteristics. It's a crucial component of the broader ISO 6346 standard, which we'll explore in more detail shortly. This code is designed for rapid identification and classification, helping everyone in the logistics chain – from port operators to customs officials – understand the basic nature of the container at a glance.

The structure of the Container Type Code is straightforward yet highly informative:

- **First Digit (Category):** This digit indicates the primary category or group of the container. It tells you the general type of container you're dealing with, such as a general-purpose dry cargo container, a refrigerated container, or a tank container.
- **Second Digit (Physical Characteristics/Attributes):** This digit provides more specific details about the container within its category. It can denote features like height, ventilation, door configuration, or other special attributes that differentiate it from other containers in the same category.

Understanding these two digits allows for immediate recognition of a container's basic function and physical makeup, which is vital for planning stowage, handling, and transport. Ocean Cargo leverages this detailed understanding to ensure your cargo is always matched with the most appropriate and compliant container type, whether you're shipping [sea freight](https://oceancargo.co.uk/services/sea-freight/) or [air freight](https://oceancargo.co.uk/services/air-freight/).

## ISO 6346: The International Standard for Container Identification

While the Container Type Code is a vital part, it operates within the larger framework of ISO 6346. This international standard, published by the International Organization for Standardization, defines the identification, marking, and coding of intermodal freight containers. Its primary purpose is to provide a uniform system for identifying containers globally, facilitating efficient intermodal transport and communication.

The full ISO 6346 identification system for a container comprises several key elements, typically found on the container's exterior:

1. **Owner Code:** Three capital letters identifying the owner or principal operator of the container (e.g., "MSK" for Maersk).
2. **Equipment Category Identifier:** A single capital letter indicating the equipment category (e.g., "U" for freight container, "J" for detachable freight container related equipment, "Z" for trailer or chassis).
3. **Serial Number:** Six digits, uniquely identifying the container within the owner's fleet.
4. **Check Digit:** A single digit used to validate the accuracy of the owner code, equipment category identifier, and serial number. This helps prevent errors in manual data entry.
5. **Size Code:** A two-digit alphanumeric code indicating the container's length and height/width. This is where the "Size" part of "Container Size/Type ISO 6346" comes in.
6. **Type Code:** The two-digit alphanumeric Container Type Code we discussed earlier, indicating the container's type and characteristics. This is the "Type" part.
7. **Country Code:** An optional two-letter code indicating the country where the container was registered.
8. **Maximum Gross Mass:** The maximum permissible weight of the container and its contents.
9. **Tare Weight:** The weight of the empty container.
10. **Net Payload:** The maximum weight of cargo that can be loaded into the container.
11. **Cubic Capacity:** The internal volume of the container.

Together, these elements provide a comprehensive identity for each container, ensuring that it can be tracked, handled, and managed effectively anywhere in the world. Ocean Cargo's expertise in [customs compliance](https://oceancargo.co.uk/services/customs-compliance/) and logistics management means we meticulously handle all aspects of container identification and documentation, ensuring your shipments meet all international standards.

## Decoding the Container Type Code: Common Examples

Let's break down some common Container Type Codes to illustrate how the two digits work in practice. While there's a comprehensive list, understanding the logic helps immensely.

### First Digit: Category (Examples)

- **G: General Purpose Container:** The most common type, used for a wide variety of dry goods.
- **R: Refrigerated Container (Reefer):** Designed for temperature-sensitive cargo.
- **U: Open Top Container:** Allows for loading from the top, suitable for oversized cargo.
- **T: Tank Container:** Used for liquids, gases, or powders.
- **P: Flat Rack Container:** No side walls, ideal for heavy or oversized cargo.
- **H: Half-Height Container:** Shorter than standard, often used for heavy bulk cargo.

### Second Digit: Specific Characteristics (Examples within 'G' for General Purpose)

For a 'G' (General Purpose) container, the second digit might indicate:

- **G0:** General purpose container, no special features.
- **G1:** General purpose container with passive vents.
- **G2:** General purpose container with active vents.
- **G3:** General purpose container with two doors (e.g., one at each end).
- **G4:** General purpose container with open sides.
- **G5:** General purpose container with open top and side doors.

So, a container marked "G0" would be a standard dry cargo box, while "R1" would likely be a refrigerated container with specific cooling capabilities. This level of detail is crucial for Ocean Cargo when advising clients on the best container for their specific goods, whether it's [sea freight to the USA](https://oceancargo.co.uk/countries/usa/sea-freight-usa) or [road freight within Canada](https://oceancargo.co.uk/countries/canada/road-freight-canada) after port arrival.

## Container Size Code: Understanding Dimensions

Alongside the Type Code, the Size Code is another two-digit alphanumeric identifier within ISO 6346 that specifies the container's length and height/width. This is critical for logistics planning, vessel stowage, and ensuring compatibility with transport [infrastructure](https://oceancargo.co.uk/industries/construction-infrastructure-logistics "infrastructure").

### First Digit of Size Code: Length

This digit typically represents the container's nominal length in feet or metres:

- **2:** 20 feet (approx. 6.096 m)
- **4:** 40 feet (approx. 12.192 m)
- **L:** 45 feet (approx. 13.716 m)
- **M:** 48 feet (approx. 14.630 m)
- **N:** 49 feet (approx. 14.935 m)
- **E:** 53 feet (approx. 16.154 m)
- Other codes exist for less common lengths.

### Second Digit of Size Code: Height and Width

This digit indicates the container's height and, in some cases, its width:

- **0:** Height 8 feet (2.438 m), Width 8 feet (2.438 m)
- **2:** Height 8 feet 6 inches (2.591 m), Width 8 feet (2.438 m)
- **5:** Height 9 feet 6 inches (2.896 m), Width 8 feet (2.438 m) (often called "High Cube")
- **6:** Height 9 feet 6 inches (2.896 m), Width 8 feet 6 inches (2.591 m) (often called "Pallet Wide High Cube")
- Other codes exist for different height/width combinations.

So, a "45G0" container would be a 40-foot (4) high cube (5) general-purpose (G) container with no special features (0). This level of detail is crucial for Ocean Cargo when planning [shipping excavators and diggers to the UAE](https://oceancargo.co.uk/countries/uae/excavators-diggers-uae), where precise dimensions are critical for [project logistics](https://oceancargo.co.uk/services/project-logistics "project logistics").

## Why These Codes Matter for Your Business

Understanding Container Type Codes and the ISO 6346 standard is not merely an academic exercise; it has tangible benefits for your business operations:

- **Accurate Quotations:** Knowing the exact container type and size needed helps Ocean Cargo provide you with precise and competitive freight quotes, avoiding surprises.
- **Optimised Cargo Loading:** Matching your cargo's dimensions and characteristics (e.g., temperature sensitivity, fragility) with the correct container type prevents damage, maximises space utilisation (whether [FCL](https://oceancargo.co.uk/services/sea-freight/fcl-full-container-load/) or [LCL](https://oceancargo.co.uk/services/sea-freight/lcl-less-than-container-load/)), and reduces costs.
- **Regulatory Compliance:** Correct container identification is vital for customs declarations and adherence to international shipping regulations, preventing delays and penalties.
- **Enhanced Safety:** Using the appropriate container type ensures the safe transport of goods, especially for hazardous materials or oversized cargo like [wind turbine components to Australia](https://oceancargo.co.uk/countries/australia/wind-turbine-components-blades-nacelles-tower-sections-australia).
- **Improved Communication:** A standardised coding system eliminates ambiguity, fostering clear communication between all parties involved in the supply chain.
- **Efficient Tracking and Management:** The unique identification system allows for precise tracking and management of containers throughout their journey, from origin to destination.

Ocean Cargo's 25 years of experience means we handle these details with precision, ensuring your cargo is always in the right hands and the right container. We simplify the complex, allowing you to focus on your core business while we manage your global logistics.

#### What is the difference between a Container Type Code and a Size Code?

The Container Type Code (e.g., G0, R1) describes the container's functional characteristics and special features (e.g., general purpose, refrigerated, open top). The Size Code (e.g., 42, L5) describes its physical dimensions, specifically its length, height, and width. Both are part of the broader ISO 6346 standard.

#### Why is the check digit important in ISO 6346?

The check digit is a single digit calculated from the owner code, equipment category identifier, and serial number. Its purpose is to validate the accuracy of the entire identification number. If even one character is entered incorrectly, the check digit calculation will fail, immediately flagging a potential error and preventing misidentification of the container.

#### Can I use any container for any type of cargo?

No. While general-purpose containers are versatile, specific cargo types require specific container types. For example, perishable goods need refrigerated (reefer) containers, liquids require tank containers, and oversized items might need open-top or flat-rack containers. Using the wrong container can lead to cargo damage, spoilage, or non-compliance with regulations. Ocean Cargo provides expert advice to ensure you always select the correct container.

#### How does Ocean Cargo help with container selection and compliance?

Ocean Cargo acts as your expert partner. Our team has in-depth knowledge of all container types and the ISO 6346 standard. We assess your cargo's specific requirements, destination regulations, and budget to recommend the most suitable and cost-effective container solution. We handle all documentation and ensure full compliance, simplifying the process for you from start to finish. [Contact us](https://oceancargo.co.uk/contact-us) for tailored advice.

### Ready to simplify your global logistics?

Get advice and a quote for your next shipment. Contact the Ocean Cargo team to start shipping.

[Freight Quote](https://oceancargo.co.uk/contact-us)

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