Universal Product Code (UPC) barcode numbers work by assigning a meaning to each of a series of twelve numbers, according to HowStuffWorks. UPC barcodes are derived from the Uniform Code Council, the company that operates the UPC system.Continue Reading
A manufacturer applies to the Uniform Code Council to enter the UPC system and pays an annual fee to use it. The UCC provides a six-digit manufacturer identification number and guidelines for using the system. This six-digit manufacturer identification number is the first half of the UPC barcode number.
The next five digits of the barcode number represent the item number. The manufacturer's UPC coordinator assigns numbers to products, assigning a different number to each item sold by that manufacturer. Different item numbers are assigned to each size packaging and to every repackaging of a product. An 8-ounce can of Folger's coffee, for example, has a different item number than a 16-ounce can.
The final digit of a UPC barcode is called the check digit, which allows the scanner to determine if it scanned the barcode number correctly. The check number is calculated by adding the digits in odd positions on the barcode, multiplying that sum by 3, and adding that number to the sum of the digits in even positions on the barcode. By determining the number that needs to be added to this value to create a multiple of 10, the check digit is formulated. This calculation is performed every time a UPC scanner scans a UPC barcode. If the calculated digit is different than the check digit, the item must be rescanned.Learn more about Business Resources