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Container packing under the CTU Code: checklist for packers and shippers

Badly packed containers cause cargo damage, accidents and pest spread. The IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code), adopted in 2014, is the global guidance on how to pack and secure cargo in containers and other transport units, and on who in the supply chain is responsible for what.

Checked against official sources: 2026-10

At a glance

Full nameIMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code)
Adopted2014, by the UNECE Inland Transport Committee, the IMO Maritime Safety Committee and the ILO Governing Body
StatusA non-mandatory global code of practice
ScopeThe whole intermodal chain, including those who pack, secure, receive and unpack units
PackerChecks the unit is undamaged, clean and pest-free, then positions and secures the cargo
ShipperClassifies and declares the cargo, including the Verified Gross Mass (VGM), to the carrier
PayloadNever exceed the payload or maximum gross mass on the CSC Safety Approval Plate or national limits
ChecklistIMO due diligence checklist MSC.1/Circ.1531, approved in May 2016

Who does what

The CTU Code applies to transport operations throughout the intermodal chain and gives guidance both to those who pack and secure cargo and to those who receive and unpack it. In the industry quick guide, the packer checks that the unit is free from damage, visible pest infestation and residues of previous cargo, and positions and secures the cargo to withstand the expected forces during transport. The shipper classifies and declares the cargo, including the Verified Gross Mass (VGM) for containers, to the carrier as early as the carrier requires. The consignor provides packaging that protects the cargo where appropriate.

Before you pack: checklist

Packing and securing

Distribute heavy cargo over the floor area and make sure the centre of gravity of the packed unit is correctly located. Do not exceed the permitted payload of the unit or the maximum gross mass allowed by national rules and the CSC plate. Prevent sliding and tipping in every direction by locking, blocking or lashing, or a combination of these. The IMO has also published informative material (MSC.1/Circ.1498) and a due diligence checklist (MSC.1/Circ.1531) to support the Code.

Step by step

  1. Choose a container type that suits the cargo and check its CSC plate.
  2. Inspect the container for damage, residues and pests, inside and outside.
  3. Make a packing plan that spreads the weight and keeps the centre of gravity correct.
  4. Secure the cargo by locking, blocking or lashing so it cannot slide or tip.
  5. Use only ISPM 15 treated and marked timber for dunnage.
  6. Weigh and declare the VGM to the carrier before the cut-off.

Documents you usually need

Common problems and how to avoid them

Cargo shifted and was damaged during the voyage.

What to do: Secure by locking, blocking or lashing against movement in every direction, and spread heavy items over the floor.

The container is rejected as overweight.

What to do: Stay within the payload and maximum gross mass on the CSC plate and national road limits, and declare an accurate VGM.

Pests are found in the container at destination.

What to do: Check the unit and cargo for visible pest contamination before packing, and use ISPM 15 timber only.

The container interior is dirty or has residues of previous cargo.

What to do: Clean it or ask for another unit before packing; the packer must check the unit is free from residues of previous cargo.

Sources

  1. IMO/ILO/UNECE Code of Practice for Packing of Cargo Transport Units (CTU Code) International Maritime Organization
  2. CTU Code – a quick guide (September 2020) COA, GSF, ICHCA International, TT Club and WSC (via IPPC)

Rules change often. This note is practical guidance based on the sources above, not legal advice. Confirm current requirements with the authority, your importer or a licensed customs broker before you ship.

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Trade notes

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Common questions

Is the CTU Code mandatory?

No. It is a non-mandatory global code of practice, but it is the reference guidance for packing containers and other transport units.

Who adopted the CTU Code?

The UNECE Inland Transport Committee, the IMO Maritime Safety Committee and the ILO Governing Body, in 2014.

Who is responsible for the VGM?

The shipper declares the Verified Gross Mass of a packed container to the carrier.

What timber can be used for dunnage?

Timber for blocking and bracing should be treated and marked in accordance with ISPM 15.

Is there a checklist for packing a container?

Yes, the IMO approved a due diligence checklist (MSC.1/Circ.1531) in May 2016, and the industry publishes a CTU Code quick guide.

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