Comparison hub
Compare All US Classification Systems
Eight classification systems, one reference hub. Compare code formats, issuing agencies, purposes, and crosswalks between them. Find the right system for your use case — federal contracting, import/export, occupational data, or procurement.
Classification Systems
Business classification — the current US federal standard
Legacy business classification (superseded by 2022)
Legacy industrial classification — still used by SEC EDGAR
Small business size standards for federal contracting
Standard Occupational Classification — jobs and careers
Product Service Codes — federal procurement classification
Global commodity classification for procurement
Export commodity codes — trade statistics
Harmonized Tariff Schedule — import duties and trade
Crosswalks & Relationships
How classification systems connect to each other.
Which system should you use?
Use NAICS 2022 for SAM.gov registration and PSC for product/service codes in solicitations. Check SBA size standards to determine if you qualify as a small business.
The SEC still uses SIC 1987 codes for EDGAR filings. If you need to convert to modern NAICS, use the SIC-to-NAICS crosswalk.
Use HTSUS to find the correct duty rate for imported goods. Each HTS code shows General, Special, and Column 2 duty rates.
US exporters use Schedule B codes for customs declarations and AES filings. Share the HS 6-digit structure with HTS but diverge at national level.
UNSPSC is the global standard for classifying products and services in procurement. PSC is the US federal equivalent used in government contracts.
SOC classifies all occupations. Use it with O*NET data for job descriptions, career exploration, and workforce statistics.
FAQ
What is the difference between NAICS and SIC?
NAICS (North American Industry Classification System) is the current US federal standard used by Census, SBA, and for SAM.gov. SIC (Standard Industrial Classification) from 1987 is legacy but still used by the SEC for EDGAR filings. NAICS uses 2–6 digit codes and covers emerging industries; SIC uses 4-digit codes with a simpler structure. Use the SIC-to-NAICS crosswalk to convert.
Schedule B vs. HTS — which do I need?
Schedule B is for US exports; HTSUS is for US imports. They share the first 6 digits (HS level) but diverge at the 8–10 digit national level. For exporting, use Schedule B. For importing and determining duty rates, use HTSUS. Search either and cross-reference.
How do SBA size standards work?
Each NAICS code may have an SBA size standard — measured in employees or annual receipts. To qualify as a small business for federal contracting, your business must not exceed the standard for your primary NAICS code. Browse SBA standards or check any NAICS code page for its specific size limit.
What's the difference between PSC and UNSPSC?
PSC (Product Service Codes) is the US federal government's procurement classification maintained by GSA. UNSPSC is an open global standard managed by GS1 and the UNDP. PSC is mandatory for US federal contracts; UNSPSC is recommended for global procurement and supply chain management.