Overview
ISO 3166-2:2020 defines the rules and guidelines for creating and maintaining country subdivision codes - the standardized codes that represent principal administrative divisions (states, provinces, regions, etc.) of countries listed in ISO 3166‑1. This fourth edition formalizes the shift to a database-centric model, aligns character usage with ISO/IEC 10646 (Unicode), and uses UTF-8 encoding for consistent, international data exchange. The code format is specified (see Key Topics).
Key Topics
- Scope and purpose: Provides basic guidelines for implementation and maintenance of current country subdivision names in coded form for any application requiring coded subdivisions.
- Code structure: Country subdivision code elements are composed of an alpha‑2 country code, a hyphen-minus, then up to 3 characters (A–Z, 0–9) - maximum length 6 characters in total.
- Language and scripts: Guidance on choice of language, romanization systems and character sets; references to ISO 639 language codes and ISO 15924 script codes are included.
- Data model and database: Codes and descriptive text moved to a single database paradigm; ISO Online Browsing Platform (ISO OBP) is the public interface for the code data.
- Maintenance and governance: Updates and stewardship are managed by the ISO 3166 Maintenance Agency (ISO 3166/MA) with procedures for name changes, code alterations, reservations and change tracking.
- Interoperability: Principles for relating subdivision codes to national/international coding systems and for ensuring one‑to‑one correspondence between names and code elements.
- Character consistency: All characters (including diacritics) checked against Unicode (ISO/IEC 10646) for consistent usage.
Applications
ISO 3166-2:2020 is used wherever standardized representation of administrative areas is needed:
- Data exchange and integration between government agencies and international organizations
- Addressing, postal services, customs and trade declarations
- Geographic Information Systems (GIS) and mapping services
- Business analytics, reporting and statistical aggregation
- E‑commerce, logistics and supply‑chain management
- Database design and APIs requiring reliable subdivision identifiers
Who uses this standard
- IT architects, database designers and developers
- National standards bodies and government administrations
- International organizations, customs and postal operators
- GIS professionals, statisticians and data analysts
- Software vendors and e‑commerce platforms
Related Standards
Using ISO 3166‑2:2020 ensures consistent, interoperable subdivision identifiers across systems, languages and borders - essential for reliable international data exchange and geographic referencing.