Hi mattj! Thank you for reaching out to us via our Customer Community! Please note that your item must be 14 digits. If you have a 12-digit UPC and your item is a consumer unit, then please add two leading zeros to the front of it. For example, it will read 00111111111111.
For a non-consumer unit, such as a case that does not have a GTIN assigned, you can add any number between 1-8 at the front. It will look something like this - 10111111111111. However, please note the last digit will change. This is called the Check Digit and it is calculated by the 13 digits that come before it. You can click on the calculator icon in the Add Items screen to have the system calculate this for you.
Please let us know if you have any further questions! Thanks!
