If you want to use bar-codes for gift cards instead of magnetic stripes, the card number range must be different from your part numbers. If you use a bar-code of 16 or more characters this will avoid conflicting with most UPC codes of 15 or less characters.

• Code 128 with 16-20 characters
• UPC-A codes starting with 1,6,8 or 9

Avoid using sequential numbering schemes as these are easy to duplicate.