Free Tool

Container Number
Validator

Check if your container number is valid. Validates ISO 6346 format, calculates the check digit, and identifies the shipping carrier. 100% free.

Format: 4 letters + 6 digits + 1 check digit (e.g. MSCU7283613)
_
_
_
_
_
_
_
_
_
_
_
Owner Code Serial Number Check

How Container Number Validation Works

Understanding the ISO 6346 standard for container identification.

1
Owner Code (4 letters)

The first 3 letters identify the container owner. The 4th letter is 'U' for freight containers, 'J' for detachable equipment, or 'Z' for trailers.

2
Serial Number (6 digits)

A unique 6-digit serial number assigned by the owner. Together with the owner code, it uniquely identifies the container worldwide.

3
Check Digit (1 digit)

Calculated using ISO 6346 algorithm. Each letter gets a numeric value, multiplied by powers of 2, summed, divided by 11 - the remainder is the check digit.

Common Container Prefixes

Quick reference for the most popular shipping line container codes.

PrefixCarrierExampleTrack
MSCUMSCMSCU7283613Track →
MEDUMSC (Mediterranean)MEDU4921834Track →
MAEUMaerskMAEU1234567Track →
MRKUMaerskMRKU9876549Track →
CMAUCMA CGMCMAU5678905Track →
HLCUHapag-LloydHLCU3456780Track →
CCLUCOSCOCCLU7890124Track →
EISUEvergreenEISU4567899Track →
ONEUONEONEU6789016Track →
ZIMUZIMZIMU3456781Track →

Container Number FAQ

ISO 6346 is the international standard for the identification of shipping containers. It defines the format: 4 letter owner code + 6 digit serial number + 1 check digit = 11 characters total.

The container number is printed on the container door, on the Bill of Lading, packing list, commercial invoice, and booking confirmation.

Each letter is assigned a number (A=10, B=12... skipping multiples of 11). Each value is multiplied by 2^position, summed, divided by 11 - the remainder is the check digit.

'U' = freight container (most common), 'J' = detachable equipment, 'Z' = trailer or chassis.

Want to track this container?

Validate the number, then track it in real-time with status updates and ETA predictions.

Track a container →