UPC-A, EAN-13, or Code 128: which barcode should you use?
Choose a retail or internal barcode format without confusing the symbol with the product identifier.
Quick answer
Use UPC-A for a valid 12-digit GTIN commonly used in North American retail, EAN-13 for a valid 13-digit retail GTIN, and Code 128 for flexible internal letters and numbers. A generated symbol does not allocate a legitimate GTIN.
Step by step
Ask the retailer or trading partner which identifier and symbol they accept. Obtain retail identifiers through the appropriate GS1 member organization, validate the check digit, and use Code 128 only when an internal workflow allows it.
Common mistakes
Do not invent UPC/EAN numbers, confuse Code 128 with GS1-128, or convert a SKU into a retail GTIN merely by adding digits. Marketplace requirements vary.
Completion check
Scan a sample into the actual POS, warehouse, or marketplace workflow and confirm that the returned identifier maps to the intended product.