Check Digit Calculator

Check your container number

Use the SCF Check Digit Calculator to determine if your container number is correct. A container number will display as incorrect if you have the wrong check digit (last number). Insert the container number in the form below and click on CHECK.

What is a Shipping Container Check Digit?

All shipping containers used for rail & sea including specialised equipment must have a unique identification number. This number is calculated from:

• The four letter prefix:  The first three letters designate the owner, the fourth is always "U" identifying the unit as a container. e.g. SCFU - SCF Containers unit
• The next 6 numbers: These numbers are decided by the owner according to their own numbering system. e.g. 205122
• The last digit:  Is called the check digit, this digit is usually outlined with a box.

You can use our calculator to work out what the check digit will be by adding the first 10 characters, or, if the check digit is valid.