What Is a Bar Code?

  • Barcodes such as UPC, EAN, and GTIN provide unique, GS1-compliant identifiers used by retailers and marketplaces worldwide.
  • UPC (GTIN-12) is the primary standard in the United States and Canada and supports accurate Amazon-compliant product identification.
  • EAN (GTIN-13) is used internationally, ensuring products are recognized consistently across global retail systems.
  • GTIN is the universal GS1 term for all barcode formats, helping marketplaces validate product authenticity.

A bar code can refer to several formats, each serving as a unique identifier for products in the marketplace. The most widely recognized is the UPC/GTIN-12 (Universal Product Code), used extensively in the United States and Canada. On a global scale, the equivalent format is the EAN/GTIN-13 (European Article Number), which helps retailers and marketplaces uniquely identify products across borders.

What is a UPC?

The UPC is a 12-digit number and encoding formula originally created for the nonprofit organization known as the UCC, now GS1. Introduced in the early 1970s, it allows retailers to efficiently track product sales, manage inventory, and ensure accurate point-of-sale information. UPC barcodes are widely accepted by major retailers and are fully compatible with Amazon’s listing requirements when sourced from GS1-compliant providers.

What is an EAN?

Developed in Europe during the late 1970s, the EAN is a 13-digit identifier managed by the former EAN foundation. Similar in purpose to the UPC, it became the global standard for product identification. The EAN foundation later merged with the UCC to form GS1, creating a unified worldwide system for product numbering.

What does GTIN mean?

GTIN, or Global Trade Identification Number, is the universal naming convention used by GS1 for all barcode formats. The number following the hyphen reflects the total digits in the code. A UPC is therefore a GTIN-12, while an EAN is a GTIN-13. This system allows retailers and marketplaces to validate product identifiers consistently across all regions.

Where is a UPC used?

Below is an illustration of a UPC/GTIN-12 bar code commonly used in the USA and Canada. This format is the foundation for retail scanning systems and supports reliable product tracking for both in-store and online marketplaces.

UPC Image

How do UPC and EAN differ?

The primary difference is the digit length: UPC contains 12 digits, while EAN contains 13. Both formats encode GS1-issued identifiers that work across retail systems, and Amazon accepts either as long as they reflect valid GS1 data.

Why are GTINs important for marketplaces?

GTINs help retailers and marketplaces verify product authenticity and maintain accurate catalogs. GS1-compliant GTINs reduce listing errors, prevent duplication issues, and ensure Amazon and other platforms recognize your product correctly.