SIC 4311 — United States Postal Service
SIC 4311 is 'United States Postal Service', a 4-digit Standard Industrial Classification (SIC) code under Major Group 43: United States Postal Service (Division E: Transportation, Communications, Electric, Gas, and Sanitary Services); it maps to modern 2022 NAICS code(s): 491110 (Postal Service).
Description & Classification
SIC code 4311 representing 'United States Postal Service' is an industry category in the Standard Industrial Classification (SIC) system under U.S. OSHA and Federal procurement registers.
Modern NAICS Crosswalk
Trace the modern equivalent classifications in the 2022 North American Industry Classification System (NAICS) database:
- NAICS 491110 - Postal Service (via SIC1987:4311→NAICS1997:49111→2002:491110→2007:491110→2012:491110→2017:491110→2022:491110)
Classification Details
| SIC Code | 4311 |
|---|---|
| Industry Title | United States Postal Service |
| Division | Division E: Transportation, Communications, Electric, Gas, and Sanitary Services |
| Major Group | Major Group 43: United States Postal Service |
| Source / Verified | US Census 1987 SIC Concordance / 2026-06-28 |
Related Resources & Compliance Guides
Further regulatory reference links for legacy SIC code 4311:
- SIC Codes Complete Compliance Guide — Detailed history and active legal applications of the SIC classification framework.
- Why Legacy SIC Codes Persist Guide — How credit systems and the SEC still rely on SIC metadata.
- SIC ↔ NAICS Crosswalk Tool — Trace industrial code conversions dynamically.
- SIC Major Group 43 Hub — View other legacy industries in this business division.
Related Industries in Major Group 43
Frequently Asked Questions (FAQ)
What industry does SIC code 4311 represent?
SIC 4311 is 'United States Postal Service', a 4-digit Standard Industrial Classification (SIC) code under Major Group 43: United States Postal Service (Division E: Transportation, Communications, Electric, Gas, and Sanitary Services); it maps to modern 2022 NAICS code(s): 491110 (Postal Service).
What is the modern 2022 NAICS mapping for SIC 4311?
SIC code 4311 maps to modern NAICS codes: 491110 - Postal Service.