The Universal Product Code (UPC) is a standardized barcode symbology managed by GS1 and used to identify retail trade items in North America. The most common variant, UPC-A, consists of 12 numeric digits encoded in a 1D linear barcode with a specific pattern of 95 bars and spaces. The first six to nine digits represent the Company Prefix (assigned by GS1 US), the next two to five digits are the Item Reference assigned by the brand owner, and the final digit is a check digit calculated from the preceding 11 digits to detect scanning errors. Every product sold through a major North American retailer requires a unique UPC.

UPC-E is a compressed six-digit variant designed for small packages where space is limited (e.g., lip balm, single-serve beverages). It suppresses leading zeros and trailing zeros in the item reference to fit the symbol into a smaller footprint. Both UPC-A and UPC-E are subsets of the broader EAN/UPC family of standards—a UPC-A barcode is technically an EAN-13 barcode with a leading zero prepended, which means European EAN-13 readers can scan North American UPCs without modification. This interoperability is critical for brands selling across global markets.

Printing accurate UPCs requires a label printer with sufficient resolution to reproduce the 0.33mm minimum module width at the intended magnification. A Zebra ZD421 or ZD621 thermal label printer with 203 or 300 dpi resolution reliably prints UPC-A labels for retail shelf tags, shipping cartons, and point-of-sale scanning. Scanning is handled by any UPC-compliant reader, including the Honeywell DS2208 general-purpose scanner used at retail checkouts and the Zebra DS3678 rugged handheld for warehouse receiving.