NAICS 517121 to SIC Code Crosswalk
The NAICS code 517121 (Telecommunications Resellers) maps transitively to legacy 1987 SIC classification code(s): 4812, 4813.
Concordance Concordance Mapping Asset
| Source Code | Source Industry | Target Code | Target Industry | Relation | Concordance Path |
|---|---|---|---|---|---|
| NAICS 517121 | Telecommunications Resellers | SIC 4812 | Radiotelephone Communications | Many-to-Many | SIC1987:4812 → NAICS1997:51333 → 2002:517310 → 2007:517911 → 2012:517911 → 2017:517911 → 2022:517121 |
| NAICS 517121 | Telecommunications Resellers | SIC 4813 | Telephone Communications, Except Radiotelephone | Many-to-Many | SIC1987:4813 → NAICS1997:51333 → 2002:517310 → 2007:517911 → 2012:517911 → 2017:517911 → 2022:517121 |
Why Concordances Don't Line Up 1:1
The Standard Industrial Classification (SIC) system was established in 1937 and last updated in 1987, organizing businesses by end products. The North American Industry Classification System (NAICS) replaced it in 1997, classifying establishments by production processes. Because of this structural shift, many-to-many relationships are common, requiring chained concordance steps to bridge the historical gap.
Reverse Crosswalk: Going the other way? See the mapping at SIC 4812 to NAICS, SIC 4813 to NAICS.
Related Pages & Tools
- NAICS Code 517121 Profile — Official definition, SBA size standards, and establishment statistics.
- Sector 51 Hub (Information) — Category directories.
- Interactive Crosswalk Engine — Convert any SIC or NAICS code dynamically.
Primary Ingestion Source
Data sourced from the U.S. Census Bureau Concordances (1997, 2002, 2007, 2012, 2017, and 2022 editions). Last verified on 2026-06-30.