What Is an ISIC Code? (ISIC Rev. 5) | International Industry Classification

Updated: 2026 · Standard: UN International Standard Industrial Classification of All Economic Activities (ISIC) · Current revision: ISIC Rev. 5 (endorsed; adoption is phased) · Governance: Authority & Trust Hub

What is an ISIC code? The International Standard Industrial Classification of All Economic Activities (ISIC) is the United Nations’ global reference system for classifying economic activity. ISIC supports international comparability by standardizing how activities are grouped and reported in official statistics (for example: national accounts, employment, and structural business statistics).

ISIC is primarily a statistical standard. National and regional systems—such as NAICS (North America) and NACE (European Union)—are designed for jurisdiction-specific measurement needs and are commonly mapped to ISIC to support international comparability.

ISIC Rev. 5 in 2026 (status and practical use)

ISIC Rev. 5 is the current UN-endorsed revision. In practice, many datasets still reference ISIC Rev. 4 while national statistical systems transition on phased timelines. For auditability, treat the revision as part of the data’s provenance: record the revision used for coding, and document any cross-revision mapping when harmonizing longitudinal data.

  • Use case fit: ISIC is the “comparability layer” for cross-border reporting and multi-country datasets.
  • Revision handling: Cross-revision conversions should be treated as analytical mappings, not identities.
  • Boundary clarity: Revisions refine definitions where real-world business models span multiple activities or where new activities require clearer delineation.

Practical rule: When assigning or converting codes, start from the predominant activity (the activity that generates the majority of value) and validate boundary cases such as outsourcing, multi-activity operations, and platform-enabled models.

ISIC conversion and lookup tools

Many users reference ISIC to translate data between global and regional systems. The tools below are designed for that workflow.

ISIC-to-NAICS cross reference

Identify likely NAICS equivalents for North American datasets. Conversions may return multiple candidates and should be validated against the unit’s primary activity.

NAICS-to-ISIC cross reference

Translate NAICS into ISIC for cross-country comparability, global benchmarking, and multi-region harmonization.

Workflow note: For multi-country datasets, standardize to ISIC (recording the revision), then map into NAICS or NACE for region-specific reporting and execution. For EU context, see: What is a NACE code?

How to read an ISIC code

ISIC is a four-level hierarchy that moves from broad groupings to detailed activity classes:

Section (Letter) Division (2-digit) Group (3-digit) Class (4-digit)

Worked hierarchy example

This example shows how a detailed class nests within a section and division.

Section
C

Manufacturing

Division (2-digit)
13

Manufacture of textiles

Group (3-digit)
139

Manufacture of other textiles

Class (4-digit)
1393

Manufacture of carpets and rugs

ISIC broad structure (top-level sections)

At the highest level, ISIC organizes economic activity into sections that span the full economy. The section set below reflects the commonly used structure for ISIC Rev. 4, which remains a widely implemented baseline during transition planning.

Section Scope label Typical coverage
AAgriculture, forestry and fishingCrop and animal production; forestry; fishing/aquaculture
BMining and quarryingExtraction of minerals; mining support
CManufacturingTransformation of materials into products
DElectricity, gas, steam and air conditioning supplyUtilities production and distribution
EWater supply; sewerage, waste management and remediationWater/waste systems and remediation activities
FConstructionBuilding and civil engineering; specialized construction
GWholesale and retail trade; repair of motor vehicles and motorcyclesWholesale/retail distribution and vehicle repair
HTransportation and storageTransport services; warehousing; logistics support
IAccommodation and food service activitiesHotels, lodging, restaurants, catering
JInformation and communicationPublishing, media, telecom, IT services and related activities
KFinancial and insurance activitiesBanking, insurance, auxiliary financial activities
LReal estate activitiesReal estate operations and services
MProfessional, scientific and technical activitiesLegal, accounting, engineering, R&D, consulting
NAdministrative and support service activitiesOffice/admin support, facilities services, travel, security
OPublic administration and defence; compulsory social securityGovernment administration and defence functions
PEducationSchooling and training
QHuman health and social work activitiesMedical services; residential care; social work
RArts, entertainment and recreationCultural activities, sports, recreation
SOther service activitiesMembership orgs, repair, personal services
TActivities of households as employers; undifferentiated goods- and services-producing activities of householdsHousehold employment and own-use production
UActivities of extraterritorial organizations and bodiesInternational organizations and similar bodies

Global vs regional classification systems

ISIC is global by design. NAICS and NACE are jurisdictional implementations designed for regional statistical and administrative needs.

System Scope Primary role Common use cases
ISIC (UN) Global International comparability Cross-country reporting, global research, harmonizing multi-region datasets
NAICS North America Regional industry measurement U.S./Canada/Mexico statistics, operational segmentation in North America
NACE European Union EU statistical and administrative alignment EU reporting, procurement/regulatory context, European datasets
SIC Primarily U.S. (legacy) Historical and legacy comparability Historical datasets and legacy administrative or vendor files

Conversion reality: A single ISIC code can map to multiple NAICS or NACE codes (and vice versa). Treat crosswalks as candidate mappings and validate against the unit’s primary activity and included/excluded definitions.

Applications of ISIC codes

  • Economic and social statistics: National accounts, employment, productivity, and industry composition.
  • Structural analysis: Monitoring economic change over time using consistent activity categories.
  • Statistical unit assignment: Classifying establishments and enterprises to support reporting and comparability.
  • International comparability: A common activity framework used across countries and international organizations.
  • Research and benchmarking: Comparative analysis of industry structure across markets and regions.

FAQ

  • Is ISIC used directly by businesses?
    ISIC is primarily a statistical standard. Many businesses primarily reference regional systems (such as NAICS or NACE) and map to ISIC for cross-country comparability.
  • What ISIC revision should I use in 2026?
    ISIC Rev. 5 is the current UN-endorsed revision. ISIC Rev. 4 remains widely implemented in existing datasets; transitions occur on phased national timelines. For defensible work, record the revision used and document any cross-revision mapping.
  • Can ISIC be converted to NAICS?
    Yes, but mappings can be non-unique. Convert, then validate the best-fit match against the unit’s predominant activity and category definitions.
    ISIC-to-NAICS Conversion Tool
  • Can NAICS be converted to ISIC?
    Yes. This is commonly used for multi-country reporting and harmonization. Validate the mapping against the organization’s primary activity.
    NAICS-to-ISIC Conversion Tool
  • How does ISIC relate to NACE?
    NACE is the European Union’s activity classification. It is designed to align with ISIC for international comparability while retaining EU-specific detail.
    What is a NACE code?

Guidance sources

These sources provide UN definitions, published ISIC materials, and UN documentation related to ISIC Rev. 5. They are provided as guidance references and do not represent endorsement by SICCODE.com.