Classification Systems
Industry Classification Crosswalks
Eight major classification systems organise the same global economy into different hierarchies. Where they align, you can move directly from one system to another. Where they differ in granularity, one system has no direct equivalent for the other’s subdivision. This site’s analysis is anchored to ISIC Rev. 4 — the UN global standard.
Why the analysis uses ISIC
ISIC (International Standard Industrial Classification) is maintained by the United Nations and serves as the bridge language between national systems. NACE, SSIC, and CNAE are all directly derived from it. NAICS aligns at the broad level. GICS uses a different organising principle (company revenue source) and only partially overlaps.
Using ISIC as the base means the analysis applies across jurisdictions. A reader comparing NACE-registered companies in Germany with NAICS-registered firms in the US can use ISIC as the common anchor.
Granularity difference: Where a national system is more granular than ISIC (e.g. NACE has three codes where ISIC has one), the site analysis covers the combined activity. Where ISIC is more specific than another system, users may need to navigate to the closest available classification.
Classification Pair Crosswalks
8 pairsDerived from ISIC
NACE Rev. 2 was directly derived from ISIC Rev. 4. Most 4-digit codes map 1:1; where NACE subdivides more finely, one ISIC class maps to several NACE classes.
Aligned to ISIC
NAICS aligns broadly to ISIC at section and division level, but diverges significantly at 5–6 digit codes where NAICS is far more granular.
Source: UN/Census Bureau concordance
Data coming soonNAICS succeeded SIC
NAICS replaced SIC in 1997. The BLS provides an official concordance. Many SIC 4-digit codes map to multiple NAICS 6-digit codes.
Source: BLS Concordance Tables (2022)
Data coming soonDerived from ISIC
SSIC 2025 aligns to ISIC Rev. 5. Because this site uses ISIC Rev. 4, mapping requires a two-step process: SSIC → ISIC Rev. 5 → ISIC Rev. 4.
Source: SingStat official (2025)
Data coming soonAligned to ISIC
ANZSIC 2006 was designed around ISIC Rev. 3.1. Alignment to ISIC Rev. 4 (used here) is partial in several service sectors.
Source: ABS official (2006)
Data coming soonDerived from ISIC
CNAE 2.0 was directly derived from ISIC Rev. 4, similar to NACE. Structural alignment is strong across all sections.
Source: IBGE official
Data coming soonBridged via ISIC
No direct NACE↔NAICS crosswalk exists. Mapping chains through ISIC: NACE → ISIC → NAICS. This introduces imprecision wherever either system is more granular than ISIC.
Bridged via ISIC
Data coming soonPartial alignment
GICS classifies companies by primary revenue source, not economic activity. Alignment to ISIC is approximate; 163 entries require manual research to complete.
Source: S&P/MSCI + manual research (planned)
Data coming soonThe Eight Systems
Rev. 4
The UN global standard underpinning all site analysis. Covers every economic activity in a 4-level hierarchy (section → division → group → class).
Browse ISIC →Rev. 2.1
The EU standard for company registration, VAT, CSRD ESG disclosures, and Eurostat statistics across all 27 member states and the EEA.
Browse NACE →2022
The current US, Canada, and Mexico standard. Uses 6-digit codes, making it significantly more granular than ISIC at the detail level.
1987
The legacy US classification replaced by NAICS in 1997. Still widely used in SEC filings, BLS data series, and historical comparisons.
2025
Singapore's national standard, updated to align with ISIC Rev. 5 from 2025. Bridging to ISIC Rev. 4 (used on this site) requires an additional mapping step.
2006
The Australia and New Zealand standard. Based on ISIC Rev. 3.1; partial alignment to ISIC Rev. 4.
2.0
Brazil's national classification system, directly derived from ISIC Rev. 4. Very close structural alignment.
2026
A financial markets classification for equity benchmarks, ETFs, and portfolio analytics. Classifies companies by primary revenue source, not economic activity — alignment to ISIC is approximate.