Industry Evolution: How SIC 7371 Became Modern Software Niches (Extended SIC + NAICS Crosswalk)

Updated: 2026
Reviewed By: SICCODE.com Industry Classification Review Team
Data Lineage: About Our Data Team

“Industry evolution” pages show how one official 4-digit SIC code can branch into modern niches using vendor-defined extended SIC categories and how those niches may map to multiple NAICS codes. This helps analysts and marketers store and apply classification data accurately across systems.

Industry Evolution Snapshot: SIC 7371 Official (4-digit)

SIC 7371 is commonly associated with computer programming services in legacy datasets. Over time, software and technology services have diversified into multiple specialized activities. Commercial datasets often represent this diversification using extended SIC-style subdivisions (often shown as 6–8 digits) while NAICS supports many modern government reporting and contracting use cases.

Governance note: Official U.S. SIC is standardized at the 4-digit level. Any 6–8 digit “extended SIC” categories are typically vendor-defined. Definitions can vary by provider, so document your source.

Quick Verdict: Which Code Should You Use?

Use NAICS when

  • Government contracts, federal reporting, and many compliance workflows
  • Cross-border comparability (US/Canada/Mexico statistical use cases)
  • You need a modern, standardized 6-digit framework

Use SIC / Extended SIC when

  • CRM segmentation, sales prospecting, and private-sector datasets
  • Legacy research and longitudinal comparisons across time
  • You want finer commercial segmentation beyond a single 4-digit SIC

How a Single SIC Code Branches Into Niches

The table below uses the directory titles shown in the SICCODE.com Extended SIC taxonomy for SIC 7371. Extended SIC labels are vendor-defined and should be treated as source-specific classifications.

Classification Level Code Official / Directory Title Example NAICS Mapping Best Use
Official SIC Official 7371 Computer Programming Services (4-digit SIC anchor) 541511 – Custom Computer Programming Services NAICS Historical comparability, legacy datasets
Extended SIC Vendor-defined 7371-02 Computer Programming Services May map to multiple NAICS options depending on delivery model Commercial segmentation and targeting
Extended SIC Vendor-defined 7371-03 Computers-System Designers & Consultants May map to systems design, integration, or related service NAICS depending on scope Commercial segmentation and targeting
Extended SIC Vendor-defined 7371-04 Data Systems Consultants & Designers May map to data-focused consulting or NAICS options depending on engagement type Commercial segmentation and targeting

Note: Crosswalks are often many-to-many. One SIC may map to multiple NAICS codes and one NAICS may include multiple SIC anchors. Best practice is to store both values when your workflows span government reporting and private-sector targeting.

Best Practices for Storing SIC and NAICS Together

Store both codes (don’t “convert on the fly”)

  • Keep the official 4-digit SIC as a stable historical anchor
  • Store NAICS separately for modern reporting and contracting workflows
  • If using extended SIC, record the provider/source taxonomy used

Document classification assumptions

  • Clarify whether classification is establishment-level or enterprise-level
  • Record the primary revenue-generating activity used to assign the code
  • Retain “effective date” or update year when available

Explore Directories and References

Bottom Line

This industry’s “evolution” is best understood as a classification layering strategy: use official SIC for continuity, use NAICS for modern reporting, and use extended SIC where commercial granularity improves segmentation—while clearly documenting the taxonomy source for any vendor-defined extensions.

Rule of Thumb: Use NAICS for government contracts, tax filings, and federal reporting. Use SIC (and extended SIC) for sales prospecting, CRM segmentation, private-sector analytics, and historical research.