Check Digit

The check digit is a character which is appended to the information characters in order to increase barcode scanning reliability. Some barcode types require the use of a check digit. As a rule, the check digit is positioned immediately in front of the stop character, and is read along with the barcode. If the check digit does not agree with the value calculated by the decoder, the barcode is not deciphered. The check digit is calculated using a specified algorithm.