check digit



  • noun the last digit of a string of computerised reference numbers, used to validate the transaction


  • noun an additional digit inserted into transmitted text to monitor and correct errors


  • A numeric digit which is added to a set of digits for error detection. When a given set of digits, such as an account number, is entered into a computer, a check digit is calculated and incorporated into it. When the number is stored, or subsequently accessed, the check digit is recomputed and compared to the original check digit.

Information & Library Science

  • noun a number added to a numeric code to enable a computer program to detect any errors in the code