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How to… Calculate your check digit

How to Check Digit The all-important check digit ensures our numbers are correct

A ll Global Trade Item Numbers (GTINs) and Global Location Numbers (GLNs) end with a computer-generated check digit.

This digit is the result of an algorithm (called the Modulo-10 algorithm) which uses the other numbers in the GTIN or GLN to ensure its correct composition. 

When you look at My Numberbank you may think that the numbers are not in sequence. This is because the last digit is a check digit based on this calculation. The preceding digits are all in sequence.

As a benefit to your membership, there is a useful online check digit calculator which can be found in the Tools & Resources menu in your account.

But if you want to understand how the check digit is calculated then take a look at our PDF, which will give you the step by step break down.

How to… Calculate your check digit (PDF)





Still confused?

We’re always available to help so contact us if you’re still unsure about how check digits.