Why is the last digit of my retail barcode wrong?
It isn't wrong. The last digit of all UPC, ISBN and EAN barcodes is called a check digit. Barcode Producer automatically calculates this for you so that an incorrect check digit can’t be used (thereby rendering an invalid barcode). You can also verify the correct check digit using GS1’s check digit calculator.
If you enter the wrong check digit, Barcode Producer will ignore your incorrect input and enter the correct check digit.