QR codes & labels
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.
Make the right call
Choose the identifier before choosing the artwork
Imagine a mug sold at a retail checkout and tracked in your own stockroom. The retail product identifier and your internal SKU serve different purposes. A checksum can detect some typing errors; it cannot prove that a number belongs to your business.
| Check | Example or action | How to judge the result |
|---|---|---|
| Retail partner requests UPC-A | Use the assigned 12-digit GTIN, including its check digit. | Confirm ownership and the partner’s requirements; never invent a number simply because the image generator accepts it. |
| Retail partner requests EAN-13 | Use the assigned 13-digit GTIN and validate its complete value. | Ask the partner how it handles leading zeros. Do not independently shorten or pad identifiers. |
| Internal stockroom uses MUG-BLUE-01 | Code 128 can represent this alphanumeric internal identifier. | Confirm the warehouse reader returns exactly MUG-BLUE-01 and maps it to one item. This is not automatically GS1-128 or a retail GTIN. |