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   Issue 9, Summer/Fall 2007

Classification Codes

Overview     SIC     NAICS     ISIC     SITC
            Other Classification Schemes


There are various systems used for industry research to classify business entities. Knowing these schemes can make some areas of research easier because some databases, many of the print sources, and the U.S. government (most notably the Census) use them in their indexing, charts, graphs, lists, and indexes. Additional information about these schemes may be found in the following resources:

Jon Haveman's Industry Concordances External Link

This site, maintained by Raymond Robertson, Associate Professor of Economics at Macalester College, provides links to a number of concordances between various systems of industry classification as well as brief descriptions of these systems.

S.I.C. Pursuits: The Consequences and Problems of Classifying Establishments for Government Statistic, by Rolf R. Schmitt and Michael Rossetti. In Proceedings of the Urban and Regional Information Systems Association: 1987, Volume IV, pp. 15-24.
Online edition

This review, prepared by the representatives of the U.S. Department of Transportation to the Technical Committee on Industrial Classification in connection with the Standard Industrial Classification System (SIC) code revision, provides a brief overview of the SIC System and discusses issued raised in relation to its revision.
BERA - Business & Economics Research Advisor - A Quarterly Guide to Business & Economics Topics

Issue 9/10: Summer/Fall 2007
Updated January 2013

Guide to Industry Research

Table of Contents

Basic Strategies
Classification Codes
Industry Sources - United States Government
Industry Sources - General
Industry Sources - Historical

Smoke stack of TVA chemical plant, 1942
Image (above):
Smoke stack of TVA chemical plant, 1942.
FSA-OWI Collection
Prints and Photographs Division
Reproduction Number: LC-DIG-fsac-1a35277

Standard Industrial Classification Code (SIC Code)

The Standard Industrial Classification (SIC) code system has been used since the 1930s. It was developed by the Interdepartmental Committee on Industrial Statistics, established by the Central Statistical Board of the United States who developed the List of Industries for manufacturing, published in 1938, and the 1939 List of Industries for non-manufacturing industries, which became the first Standard Industrial Classification for the United States. The SIC system was last revised in 1987 and last used in the 1992 Economic Census. The system is broken down into 10 Divisions (A-J) and each is then divided into Major Groups (2 digits) and then into specific 4 digit numbers. Included are the previous editions for historical purposes.

Internet Resources

History of the Standard Industrial Classification
Archived at:
From the introduction by Esther Pearce to the 1967 SIC Manual (misidentified on the site as 1957).
Standard Industrial Classification (SIC) System Search
This page from the Occupational Safety & Health Administration of the U.S. Dept. of Labor offers a search of the 1987 version of the SIC manual by keyword, to access descriptive information for specified 2,3,4-digit SIC's, and also allows users to browse the manual itself.
SIC Manual
A direct link to the SIC Manual, from the Occupational Safety & Health Administration of the U.S. Dept. of Labor.

SIC Manual (1941-1972)

Digitized 1941-1972 editions are available in full text from Hathi Trust Digital Library.

Print Resources

Standard Industrial Classification Manual : 1987 / [prepared by the] Executive Office of the President, Office of Management and Budget. The Office : [Supt. of Docs., U.S. G.P.O. distributor] ; Springfield, Va., 1987.
LC Call Number: HF1042 .S73 1987
LC Catalog Record: 87602335

1982 Industry and Product Classification Manual. [Washington, D.C.] : U.S. Dept. of Commerce,
Bureau of the Census, 1982.
LC Call Number: HF1042 .A614 1982
LC Catalog Record: 83601059

Standard Industrial Classification Manual. Prepared by the Statistical Policy Division. [Washington; For
sale by the Supt. of Docs., U.S. Govt. Print. Off.] 1972.
LC Call Number: HF1042 .A55 1972
LC Catalog Record: 72601529

Standard Industrial Classification Manual. Prepared by the Technical Committee on Industrial
Classification Office of Statistical Standards. [Washington, D.C.?] : Executive Office of the President,
Bureau of the Budget ; Washington, D.C. : U.S. G.P.O., 1957.
LC Call Number: HA40.I6 U63 1957
LC Catalog Record: 57060793

Standard Industrial Classification Manual. Washington, U. S. Govt. Print. Off. [1946]-49.
LC Call Number: HA40.I6 U63
LC Catalog Record: 46026143

Standard Industrial Classification Manual. [Washington, 1942]
LC Call Number: HA40.I6 U623 1942
LC Catalog Record: 51053502


In 1997 the North American Industrial Classification System (NAICS) was developed to replace the SIC code and is designed to be renewed/revised every 5 years. It was developed jointly by the U.S., Canada, and Mexico in order to provide new comparability in statistics about business activity across North America. NAICS identifies hundreds of new, emerging, and advanced technology industries and reorganizes industries into more meaningful sectors — especially in the service-producing segments of the economy. Generally, the NAICS are much better at covering the industries that exploded in the 1990's — e-commerce and related areas, biotechnology, heavily technical areas, etc. For a further discussion go to Census' explanation.

While the system is organized somewhat like the SIC, the numbers are not necessarily comparable. However, the Economic Census web page does offer various conversion tools to bridge between the SIC and various NAICS versions so you can match data under the systems when doing research for the time frame when the government started to use the NAICS system or doing research comparing older data to current.

Internet Resources


NAICS home page from the U.S. Bureau of the Census.

NAICS (Statistics Canada) External Link

NAICS home page from Statistics Canada.

2012 NAICS Codes and Titles

Print Resources

North American Industry Classification System: Canada 2002. [Ottawa] : Statistics Canada, c2003.
LC Call Number: HF1041.5 .N67 2003
LC Catalog Record: 2003447178

North American Industry Classification System : United States. / Executive Office of the President,
Office of Management and Budget. Washington, DC : Executive Office of the President : Office of
Management and Budget : For sale by the U.S. G.P.O., Supt. of Docs., 1997.
LC Call Number: HF1041.5 .N674 1997
LC Catalog Record: 98203884

North American Industry Classification System : United States, 2002 / Executive Office of the President,
Office of Management and Budget. 2002 Rev. Lanham, MD : Bernan ; Springfield, VA : National
Technical Information Service, 2002.
LC Call Number: HF1042 .N67 2002
LC Catalog Record: 2003387616

North American Industry Classification System : United States. / Executive Office of the President, Office of Management and Budget. Lanham, MD : Bernan, 1998-
Includes 2007 and 2012 editions.
LC Call Number: HF1042 .N67
LC Catalog Record: 2002249052


International Standard of Industrial Classification (ISIC) of All Economic Activities code was developed by the UN as a standard way of classifying economic activities. The ISIC code groups together enterprises if they produce the same type of goods or service or if they use similar processes (i.e. the same raw materials, process of production, skills or technology). This tends to be used cross border or in international sources.

Revision 3.1 (4 is in revision) External Link

International Family of Economic and Social Classifications External Link


The Standard International Trade Classification (SITC) is used in the compilation and comparison of trade statistics. The commodity groupings of SITC reflect (a) the materials used in production, (b) the processing stage, (c) market practices and uses of the products, (d) the importance of the commodities in terms of world trade, and (e) technological changes.

Revision 3 External Link

Available online in English and Spanish. Revision 3 was issued in 1986.

Revision 4 External Link

SITC, Rev. 4 was accepted by the United Nations Statistical Commission at its thirty-seventh session (March 2006). The Interagency Task Force on International Merchandise Trade Statistics recommends SITC, Rev. 4 for use in the analysis of international merchandise trade by interested countries and international organizations. From the home page


NACE (Eurostat) External Link

Officially known as the Statistical Classification of Economic Activities in the European Community, both the Rev 1.1 (2002) and the Rev 2 (2007) editions are available from the Quick Links section of the above page. The NACE (Rev.1.1 2002) classification of economic activities corresponds to ISIC Rev.3 at European level. The NACE (Rev 2 2007) edition corresponds to ISIC Rev. 4 at the European level.

United Kingdom Standard Industrial Classification of Economic Activities (UKSIC) External Link

This United Kingdom classification scheme "is Identical to the EUROSTAT System NACE at the four digit class level and the United Nations system ISIC at the two digit Divisional level." From the home page

Last Updated: 02/23/2018

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  February 23, 2018
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