The North American Industry Classification System (NAICS) is the new standard coding system developed to describe business establishments and industries, replacing the Standard Industrial Classification (SIC) codes.
NAICS applies a 6-digit numbering hierarchy to organize industries for Canada, Mexico, and the United States.
Read more about industry codes.
The Quarterly Census of Employment and Wages (QCEW) program at the Bureau of Labor Statistics (BLS) derives its industry data from quarterly tax reports submitted to State Employment Security Agencies by over eight million employers.
Read more.