Understand where UPC, EAN, and Code 128 are commonly used and what a generator cannot do.
UPC, EAN, and Code 128 can look similar to a newcomer, but they serve different workflows. The receiving system decides which symbology and data structure are acceptable.
UPC and EAN
UPC-A is widely associated with retail items in the United States and Canada, while EAN-13 is common internationally. These symbols normally carry a Global Trade Item Number structure. The number must come from an appropriate allocation process; making up digits and generating bars does not create a valid product identity.
Code 128
Code 128 supports a broad character set and is efficient for internal inventory, shipping labels, and supply-chain applications. It does not by itself define what the encoded string means. A warehouse, carrier, or software system may require an application-specific pattern, check data, or GS1 element strings.
Check digits are not registration
Some formats calculate a final check digit to detect common scanning or typing errors. A mathematically correct check digit only shows that the number follows the calculation. It does not prove ownership, uniqueness, authenticity, or marketplace approval.
Before generating artwork
- Ask the retailer, carrier, marketplace, or software vendor for the required format.
- Obtain identifiers through the appropriate organization.
- Enter the data exactly and preserve leading zeros.
- Follow size, quiet-zone, color, and print-quality specifications.
- Test with the production scanner.
For retail identification, begin with the official GS1 overview and your local GS1 member organization.