The last digit of a barcode number is a computer check digit which makes sure the barcode is correctly composed. Use our check digit calculator below to calculate a check digit.
Check digit calculator
![barcodes_checkdigit](https://www.gs1ae.org/wp-content/uploads/barcodes_checkdigit.gif)
Calculate a check digit
What is a check digit?
The last digit of all fixed-length, numeric GS1 Identification Keys is a check digit that ensures the integrity of the key.
All GS1 ID Keys need a check digit, except Component/Part Identifier (CPID) and Global Individual Asset Identifier (GIAI). Global Model Number (GMN) includes a pair of check characters rather than a single check digit.
How does the check digit calculator work?
The check digit is calculated using a simple algorithm, based on the other numbers in the key.
Find out how to calculate a check digit manually.
Find out more
Easy use of GS1 standards with digital services and smart online tools.
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The GS1 General Specifications
This document describes how GS1 barcodes and identification keys should be used.
![1012-1](https://www.gs1ae.org/wp-content/uploads/1012-1.jpg)
GS1 identification keys
GS1 ID Keys give companies efficient ways to access information about items in their supply chains, and share this information with trading partners.
![barcode_spar](https://www.gs1ae.org/wp-content/uploads/barcode_spar.jpg)
Who owns this barcode?
You can know about the owner of a barcode thanks to our tool.