SIC and NAICS Codes
What are SIC codes?
Standard Industrial Classification (SIC) codes are four digit numerical codes assigned by the U.S. government to business establishments to identify the primary business of the establishment. The classification was developed to facilitate the collection, presentation, and analysis of data; and to promote uniformity and comparability in the presentation of statistical data collected by various agencies of the federal government, state agencies, and private organizations. The classification covers all economic activities: agriculture, forestry, fishing, hunting, and trapping; mining; construction; manufacturing; transportation; communications, electric, gas, and sanitary services; wholesale trade; retail trade; finance, insurance, and real estate; personal, business, professional, repair, recreation, and other services; and public administration.
Reading SIC Codes
The first two digits of the code identify the major industry group, the third digit identifies the industry group, and the fourth digit identifies the industry. For example:
20 Food and Kindred Products
209 Miscellaneous Food Preparations and Kindred Products
2096 Potato Chips, Corn Chips, and Similar Snacks
To make it easier to identify specific industries or even particular
products, some sources, such as the Predicasts F&S Index, expand
the code to as many as seven digits. For example:
36 Electronic and Other Electrical Equipment and Components, Except Computer Equipment
367 Electronic Components and Accessories
3674 Semiconductors and Related Devices
3674125 Random Access Memory Circuits [Predicasts F&S Index code]
Note that the digit "9" is used in the third- or fourth-digit position of the classification code to designate miscellaneous industries not elsewhere classified. These miscellaneous classifications are not comprised of homogeneous primary ctivity groups. They are grouped together and treated as a separate industry in order to retain the homogeneity of the other industries in the group.
What is NAICS?
The North American Industry Classification System (NAICS) is a new economic classification system that replaces the 1987 SIC system for statistical purposes. Like the SIC, NAICS is a system for classifying establishments by type of economic activity. Although the principles of the system are the same as for the SIC system, individual industry classification numbers are longer (6 digits) and may vary considerably from the SIC codes. This new system was developed jointly by the U.S., Canada, and Mexico, to make international comparisons easier. Starting with federal data collected for 1997 in the United States and Canada and 1998 for Mexico, the new NAICS codes apply. The 1997 Economic Census was the first to use the new system. The Official Notice announcing the implementation of the NAICS provides an excellent explanation of the new system and its origins. Information about this new system is available at several sites:
- The North American Industry Classification System (NAICS) official page includes links to tables comparing the 1987 SIC to the 1997 NAICS.
- The North American Industry Classification System (NAICS ): Unofficial Clearinghouse provides information and links to sites concerning NAICS.
- How NAICS Will Affect Data Users
Paul T. Zeisset and Mark E. Wallace of the Economic Planning and Coordination Division, Bureau of the Census, explain how NAICS makes substantial structural improvements and identifies over 350 new industries, but it causes profound breaks in time series.
Reading NAICS Codes
The NAICS is arranged in a hierarchical structure similar to the SIC. The first two digits identify a major Economic Sector [formerly Division], the third digit designates an Economic Subsector [formerly Major Group], the fourth digit designates an Industry Group, and the fifth digit designates the NAICS Industry. For example, the NAICS number for potato chips is:
31 Manufacturing
311 Food Manufacturing
3119 Other Food Manufacturing
31191 Snack Food Manufacturing
311919 Other Snack Food Manufacturing
The internationally agreed upon NAICS system determines only the first five digits of the code. Use of a sixth digit permits the individual countries to specify subdivisions suited to the country. Thus, 5-digit codes are standardized across the three countries, but at the 6-digit level the U.S. codes may differ from those in Canada or Mexico.
Where are SIC and NAICS codes listed?
To identify the SIC code for an industry or product, consult:
- Standard Industrial Classification Search from OSHA, which permits online searching by keyword or number.
- Standard Industrial Classification Manual (Ref HF 1042 .S73 1987)
Published by the Office of Management and Budget, the manual is the official guide to the SIC codes assigned to establishments by the federal government. The body of the manual is arranged by SIC code. A detailed alphabetic index is provided, as is a numerical listing of short titles for the industries.
- Standard & Poor's Register of Corporations
- the alphabetic listing at the front of volume one of the Predicasts F&S Index for any year
To find the SIC code for a firm, use company resources, such as:
- Dun & Bradstreet's Million Dollar Directory (Ref HC 102 .D8)
Its Industry Cross-Reference section lists companies under the four digit SIC codes, which are arranged in numerical order. Many companies have multiple listings, depending on the various lines of business in which the company is engaged.
To identify NAICS codes, consult:
- 1997 U.S. NAICS Codes and Titles
Issued in July 1998, this is a list of codes and titles by code number.
- 1997 NAICS and 1997 SIC Correspondence Tables
Provides tables linking the two systems, from SIC to NAICS and from NAICS to SIC.
- North American Industry Classification System - United States, 1997. (Ref. HF 1042 .N67 1997)
The NAICS manual, it replaces the SIC Manual listed above.
To find the NAICS code for a firm, use company resources, such as:
- Standard & Poor's Register of Corporations, Directors and Executives (Desk Ref HG 4057 .A401)
Volume two contains both an alphabetical and numerical listing of the major industrial sectors and an index of all companies listed in the Register by NAICS number. Many companies have multiple listings, depending on the various lines of business in which the company is engaged.
How are SIC and NAICS Codes used?
You can use the SIC or NAICS code to find information about the industry in many sources, including:
- Economic Census
Beginning with the 1997 census, NAICS is used; earlier censuses use SIC codes.
- various business ratio sources
- Predicasts F&S Index (Index Tables, Floor 4)
Comprised of three indexes to business periodicals, covering the United States, Europe, and International. Each index contains information from hundreds of financial publications, business oriented newspapers, trade magazines, and special reports. Each index has two sections: company and industry/product. The company section is arranged alphabetically by company name. The industry/product section is arranged by major industry groups using a modified SIC number system. An alphabetical guide to SIC numbers appears at the front of the volume.
International Classification Systems
Several product and activity classification systems are in use internationally. Principal among them are:
- The Harmonized Commodity Description and Coding System, generally referred to as "Harmonized System" or "HS", is an international product classification developed by the World Customs Organization (WCO). It comprises about 5,000 commodity groups, each identified by a numeric code. The system is used by more than 177 countries and economies as a basis for their Customs tariffs and for the collection of international trade statistics. Over 98% of the merchandise in international trade is classified in terms of the HS. The codes can be expressed at the 4-digit, 6-digit, or 10-digit level.
- International Standard Industrial Classification -- ISIC
The hierarchical structure may be viewed at the University of Rome site, or a simple list of the 2-digit main divisions is available at the ILO's International Standard Industrial Classification of All Economic Activities.
- Standard International Trade Classification System, Revision 3 -- SITC
Can be viewed at the 1-digit, 2-digit, 3-digit, or 4-digit level.
Other helpful sources include:
Milner Library, Illinois State University
Page Contact: Katherine M. Weir, Business Librarian
E-mail comments to: kmweir@ilstu.edu
Last revised: August 10, 2004
