Overview
ISO/IEC 15420:2025 - Information technology - Automatic identification and data capture techniques - EAN/UPC bar code symbology specification - is the international standard that defines the EAN/UPC bar code symbology used worldwide for retail and logistics identification. The third edition (2025) specifies the symbology characteristics, character encodation, symbol formats, dimensions and tolerances, decoding algorithms, verification and quality requirements, and symbology identifier prefixes. Data content rules (for example GTIN assignment) are intentionally outside its scope and are maintained in the GS1 General Specifications.
Key technical topics and requirements
- Encodable character set: numeric (digits 0–9) per ISO/IEC 646.
- Symbology types: EAN-13, UPC-A, UPC-E (each may include add-on symbols) and EAN-8.
- Character structure: each data character is encoded as a 7-module pattern (4 elements: 2 bars and 2 spaces) from number sets A, B and C with defined parity behavior.
- Symbol mechanics: continuous symbology, omni-directional decoding capability, and a mandatory single symbol check digit.
- Dimensions & tolerances: measurement basis and parameters such as narrow element (X) width, bar height, quiet zone, element widths, symbol width/size and dimensional tolerances are specified.
- Decoding: a reference decode algorithm and application-defined parameters are provided to ensure interoperability.
- Quality & verification: test methodology, decodability metrics and additional quality criteria; verification lighting updated in this edition from 670 nm to 660 nm to align with GS1.
- Auxiliary and guard patterns: definitions for normal/centre/special guard patterns and add-on patterns.
- Normative annexes and informative guidance: include additional features, symbology identifier strings, an overview of the GS1 system, dimensioned drawings and printing/reading guidelines.
Practical applications and who uses this standard
- Manufacturers of barcode printers, scanners and verifier equipment ensuring correct encoding and reliable decoding.
- Software developers implementing barcode generation, decoding algorithms, and label layout engines.
- Retailers, distributors and logistics operators implementing AIDC for point-of-sale (POS), inventory tracking and supply-chain automation.
- Standards bodies and testing laboratories performing barcode conformance and print quality verification.
- Integrators and consultants working with GTIN and GS1-based identification systems.
Related standards
- GS1 General Specifications (data content and assignment rules)
- ISO/IEC 15416 - Bar code print quality test specification - Linear symbols
- ISO/IEC 19762 - AIDC vocabulary
ISO/IEC 15420:2025 is essential for interoperable EAN/UPC implementation across the retail and logistics ecosystem, providing the technical baseline for consistent barcode production, verification and decoding. Keywords: ISO/IEC 15420:2025, EAN/UPC, barcode symbology, AIDC, GTIN, GS1, decoding algorithm, barcode verification, dimensions and tolerances.