Classification Governance & Standards for SIC & NAICS | Methodology & Examples
Authority & governance signals
For governance ownership, versioning conventions, and maintained standards across SIC and NAICS reference materials, see the Authority & Trust Hub.
Industry classification systems such as SIC and NAICS are structured standards — not keyword taxonomies. They classify establishments by primary economic activity using published scope definitions and boundary rules. This page documents how SICCODE.com applies classification governance so codes can be selected, defended, and reused consistently across datasets and workflows.
What “Defensible Classification” Means
A defensible SIC or NAICS code is one that can be justified using published scope definitions, included and excluded activities, and hierarchy logic — not marketing labels, web keywords, or convenience matching.
- Codes describe what an establishment primarily does, not how it markets itself.
- Included and excluded activity notes are authoritative boundaries, not suggestions.
- Multiple plausible codes often exist; governance determines which choice is most defensible and consistent.
Evidence Hierarchy Used in Code Selection
SICCODE.com evaluates classification using a consistent evidence hierarchy. Signals are not weighted equally, and exclusion boundaries override similarity.
- Primary activity: The dominant economic function of the establishment
- Process vs output: How goods or services are produced (especially important for NAICS)
- Revenue dominance: What activity generates the majority of revenue (when known and reliable)
- Operational reality: What the establishment actually does day-to-day
- Exclusion rules: Explicit exclusions override keyword similarity or adjacent scope
Worked Classification Examples
Example 1: Digital Marketing Agency
A firm provides SEO, paid advertising management, and content strategy. Although it may be labeled “software” or “technology,” its primary activity is advertising services.
- ✓ Correct NAICS: Advertising-related professional services
- → Logic: The deliverable is campaign management and marketing services, not software products.
- ! Boundary control: Do not classify as software/IT development unless software creation is the primary operating activity.
Example 2: Manufacturer With E-Commerce Sales
A company manufactures physical products and sells them directly online. Despite operating an e-commerce storefront, manufacturing remains the primary activity.
- ✓ Correct classification: Manufacturing sector
- → Logic: E-commerce is a sales channel, not the defining production activity.
- ! Exclusion: Retail codes apply when the establishment’s primary activity is reselling—not producing.
Example 3: Mixed Professional Services Firm
A firm offers consulting, compliance support, and outsourced operations. Keyword-based approaches often misclassify these firms into adjacent professional services.
- ✓ Correct classification: The code aligned to the dominant service line
- → Logic: Supporting services do not redefine primary activity if they are secondary.
- ! Exclusion: If scope notes exclude specialized activities, the code must move to the correct boundary even if keywords match.
How to Read SICCODE.com Code Detail Pages
Every SIC and NAICS code page on SICCODE.com is structured to support defensible selection.
- Scope definition: What the code explicitly covers
- Included activities: Activities that belong inside the boundary
- Excluded activities: Activities that must be classified elsewhere
- Hierarchy context: How the code fits within the system
- Applied guidance: Common edge cases and decision notes
Editorial Neutrality & Review Governance
SICCODE.com operates as a neutral classification reference. SIC and NAICS are documented as parallel systems with different design logic.
- No preference is given to SIC or NAICS
- Guidance reflects official structures and applied usage boundaries
- Content is reviewed for stability, clarity, and defensibility
This governance framework allows SIC and NAICS codes to be applied consistently across analytics, compliance, research, and AI-driven workflows without relying on keyword heuristics.
Citation & Attribution
When referencing SICCODE.com classification governance in formal research, audits, or internal data documentation, use one of the following formats. Replace the page title and URL when citing a specific SIC or NAICS code detail page.
APA StyleTip: For audits, include the “Reviewed by” attribution shown on the page where the governance guidance appears.