What does an ISO 6346 size and type code look like?

It is four characters, for example 22G1. The first character is the length, the second is the height and width, the third is a letter for the container type, and the fourth is a numeric subtype. It is shown on the container alongside the owner code and check digit.

What does the code 22G1 mean?

22G1 is a 20-foot, standard-height general-purpose dry box. The first 2 means 20 feet long, the second 2 means 8 feet 6 inches high, G means general purpose with no ventilation, and the 1 is the standard subtype. It is the most common container type in service.

How do I tell a high-cube container from the code?

Look at the second character. A digit of 5 means a height of 9 feet 6 inches, which is a high-cube container, while 2 means the standard 8 feet 6 inches. So 45G1 is a 40-foot high-cube dry box and 42G1 is a 40-foot standard-height one.

What is the difference between the size code and the BIC owner code?

The size and type code is the four-character group describing the box's dimensions and type. The BIC owner code is a separate 11-character identifier: four letters for the owner and category, six serial digits, and a check digit. They appear together but encode different things.

Which type letter is a refrigerated container?

The letter R in the third position marks a refrigerated container, or reefer. R0 and R1 are integral reefers with their own refrigeration unit, while R2 and R3 are insulated boxes served by an external clip-on plant. So 45R1 is a 40-foot high-cube integral reefer.

What is the ISO 6346 Container Type Code Reference?

Decode the four-character ISO 6346 container size and type code into length, height, and container type. Includes a reference of type groups (general purpose, reefer, open top, flat rack, tank) and common full codes used on shipping documents. It runs free in your browser on Gera Tools, with nothing uploaded.

ISO 6346 Container Type Code Reference

Name: ISO 6346 Container Type Code Reference
Creator: Gera Tools
License: https://creativecommons.org/licenses/by/4.0/

Decoding the container size and type code

Every ISO shipping container carries a four-character size-and-type code defined by ISO 6346, such as 22G1 or 45R1. It tells you the box’s length, its height and width, and what kind of container it is. This tool splits a code into those parts and lists the type groups and the common full codes you will meet on bills of lading and container interchange reports.

How it works

The four positions are read independently:

position 1 : length   (2 = 20 ft, 4 = 40 ft, L = 45 ft)
position 2 : height/width (2 = 8'6", 5 = 9'6" high-cube)
position 3 : type letter  (G general, R reefer, U open-top, P flat-rack, T tank)
position 4 : subtype digit (variant within the type)

So 22G1 decodes as 20 ft long, 8 ft 6 in high, general-purpose dry box, standard subtype. Change the second character to 5 and 25G1 would be high-cube; change the first to 4 and 42G1 is the 40-foot version. The type letter drives the most important distinction — a plain dry box, a reefer, an open top, a flat rack, or a tank.

Common codes at a glance

Code	Length	Height	Type	Typical cargo
22G1	20 ft	8’6”	General purpose	Dry goods, cartons, pallets
42G1	40 ft	8’6”	General purpose	High-volume dry cargo
45G1	40 ft	9’6”	High-cube GP	Lightweight voluminous cargo, furniture
L5G1	45 ft	9’6”	High-cube GP	European road/rail swap-body equivalent
22R1	20 ft	8’6”	Integral reefer	Chilled or frozen perishables
45R1	40 ft	9’6”	High-cube reefer	Large-volume perishables, pharmaceuticals
22U1	20 ft	8’6”	Open top	Machinery, steel coils, out-of-gauge height
42P1	40 ft	variable	Flat rack	Heavy machinery, vehicles, project cargo
22T1	20 ft	n/a	Tank container	Bulk liquids, chemicals, food-grade products

Understanding the type letter in detail

The third-position letter is the most operationally significant character:

G — General purpose. The standard dry box with solid walls, roof, and swing doors. G0 has ventilation plugs; G1 does not. Most containers on the water are G1.
R — Refrigerated (reefer). Integral refrigeration machinery built into the front wall; plugs into ship or terminal power. R1 is the most common; R2 and R3 are insulated but cooled by an external clip-on plant.
U — Open top. No roof or a removable tarpaulin roof, for cargo loaded from above (cranes, bulk chutes) or cargo taller than a standard box.
P — Flat rack and platform. Collapsible end walls or no walls at all; used for overwidth, overheight, or very heavy project cargo that cannot fit inside a box.
T — Tank. A cylindrical tank inside an ISO frame; used for hazardous or non-hazardous bulk liquids. T1–T6 cover carbon-steel tanks for mild chemicals; T7–T12 are stainless steel for aggressive products.
H — Insulated / thermal. No refrigeration machinery; relies on precooling and insulation.

Tips and notes

Do not confuse the size-and-type code with the 11-character BIC owner code (four letters then seven digits, the last a check digit) stencilled above it. The two sit together on the container door but answer different questions: who owns it versus what shape and type it is.

High-cube boxes (9 ft 6 in, position-2 digit = 5) are about 30 cm taller than standard boxes and may not fit under some bridge or warehouse clearances — they usually carry a black-and-yellow stripe to warn handlers of the extra height.

On shipping documents the size-and-type code appears in the “container type” field of the bill of lading, the equipment interchange receipt (EIR), and the cargo manifest. If the code on the document does not match the box stencilled on the door, flag it before signing the EIR — discrepancies can affect cargo liability and customs entries.