SIC Codes &NAICS Codes

Standard Industrial Classification (SIC) codes are four-digit codes used to identify an industry.

The North American Industry Classification System (NAICS) is gradually replacing the SIC system. The NAICS system uses six-digit codes to identify an industry. The first five digits are standardized in the United States, Canada, and Mexico.

Many sources provide industry information based on these codes. Also, most directories that index companies by industry use SIC and/or NAICS codes.

For the next couple of years, you may need to use both SIC and NAICS codes in your research. Even after all resources have switched to NAICS codes, you may still need to use SIC codes if doing historical research.

Most resources that utilize these codes provide their own index to the codes. There are also detailed guides specific to SIC or NAICS codes as well as correspondence tables (see below). If you are unable to determine the appropriate SIC code for an industry but know a company that is part of that industry, look up a company profile to see what codes are assigned to that company.

NOTE: The codes are standardized to the four or six digit level. Some sources will add additional digits to further specify an industry. These additional digits may or may not be uniform in different sources.

NOTE: The codes themselves are an accepted standard, but the assigning of codes to companies is not centralized or standardized. Each source will assign codes based upon how the publisher/producer interprets what the company does and upon which industries of a large conglomerate are considered the most important. Thus different sources often list varying codes for a particular company.

Sources for Determining SIC Codes:

Standard Industrial Classification Manual
AVAILABILITY: Reference. (HF1042 .A55 1987)

OSHA SIC Manual from The United States Department of Labor is an online, searchable version of the SIC Manual.
AVAILABILITY: http://www.osha.gov/cgi-bin/sic/sicser5

 

NAICS Association provides a search tool to find NAICS and SIC codes.
AVAILABILITY: http://www.naics.com/search.htm

 

WSA Corp. - Provides the basic outline but lacks detailed descriptions.
AVAILABILITY: http://www.wsacorp.com/sic.html

Sources for Determining NAICS Codes:

North American Industry Classification System: The official manual.
AVAILABILITY: Reference. (HF1042 .A55 1997)

U.S. Census Bureau provides a list of NAICS codes.
AVAILABILITY: http://www.census.gov/epcd/naics/naicscod.txt

 

NAICS Association provides a search tool to find NAICS and SIC codes.
AVAILABILITY: http://www.naics.com/search.htm

Correspondence/Conversion Tables:

North American Industry Classification System: See Part III.
AVAILABILITY:Reference. (HF1042 .A55 1997)

Correspondence Tables from the U.S. Census Bureau.
AVAILABILITY: http://www.census.gov/epcd/www/naicstab.htm

Additional Resources on NAICS and SIC Codes:

An Unofficial Clearinghouse Concerning NAICS
AVAILABILITY: http://www.library.georgetown.edu/bic/help/naics/index.htm

 

NAICS Association
AVAILABILITY: http://www.naics.com/index.html

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