History of SIC Codes

Standard Industrial Classification (SIC) Codes continue to play a vital role in the United States economy.  While initially intended for statistical purposes, SIC codes have evolved into a very valuable tool for business marketing and evaluating marketplaces.

Beginning of SIC Codes

Industrial Classification originated in a recommendation at an Interdepartmental Conference on Industrial Classification held in 1934. This recommendation, which was transmitted to the Central Statistical Board, suggested that there should be an established continuing committee to explore the problems of industrial classification of statistical data. In 1937, the Central Statistical Board established an Interdepartmental Committee on Industrial Classification ''to develop a plan of classification of various types of statistical data by industries and to promote the general adoption of such classification as the standard classification of the Federal Government.

At its first meeting on June 22,1937, a Technical Committee was established to work on the preparation of the proposed standard classification of industries. Standardization in this field was an important objective since various agencies collecting industrial data used their own classifications. Therefore, a given establishment might be classified in one industry by one agency and in another by a second agency. Such a situation made the comparison of industrial data prepared by different agencies difficult and often misleading.

The project was designed to classify "industry" in the broad sense of all economic activity; i.e., agriculture, forestry, and fisheries; mining; construction; manufacturing; wholesale and retail trade; finance, insurance, and real estate; transportation, communication, electric, gas, and sanitary services; and services. The Technical Committee worked first on manufacturing industries, and in June 1938 a list of industries was accepted by the Interagency Committee. This Committee, at the same meeting, discussed coding problems in nonmanufacturing fields, and decided to authorize the establishment of subcommittees of experts in various nonmanufacturing fields to prepare proposed classifications.This led to the creation of the Lists of Industries. The List of Industries for manufacturing was first available in 1938, with the List of Industries for nonmanufacturing following in 1939. These Lists of Industries became the first Standard Industrial Classification (SIC) for the United States.

The first edition of the Standard Industrial Classification Manual was put out in duplicated form as follows: 

Volume I, Manufacturing Industries 

• Part 1 - List of Industries., 1938
• Part 2 - Description of Industries, 1940
• Part 3 - Alphabetic Index of Products, Establishments and Processes, 1939
• Part 4 - Alphabetic Index of Products, Establishments and Processes by Major Groups, 1939

Volume II - Nonmanufacturing Industries 

• Part 1 - List of Industries, 1939
• Part 2 - Description of Industries, 1940
• Part 3 - Alphabetic Index of Products, Establishments, and Services, 1940
• Part 4 - Alphabetic Index of Products, Establishments and Services by Major Groups, 1940

SIC Code Revisions

After the 1939 SIC had been in use for a reasonable length of time, the Central Statistical Board transferred the project to the Bureau of the Budget.  A review was conducted and appropriate revisions were made. Following the review, the first printed edition of Manufacturing Industries was published in 1941 and that of Nonmanufacturing Industries in 1942.

In 1945, a new edition of Volume I, Manufacturing Industries, of the Standard Industrial Classification Manual was published in two parts:

• Part 1, Titles and Descriptions of Industries, November 1945
• Part 2, Alphabetic Index, December 1945

This reflected the technological advances in industry developed throughout World War II, as well as changes recommended by users of the 1941 classification. A revision of Volume II, Nonmanufacturing Industries, was published in 1949.  This, as well as the 1945 Manufacturing, was based on the same general principles and prepared with the same type of committee structure as were the earlier issues of the Standard Industrial Classification Manual.

The revised Standard Industrial Classification, combining both manufacturing and nonmanufacturing industries into one book, was published in July 1957. A review of the 1957 edition of the Manual, based on data from the 1957 Economic Censuses for all in-scope industries, and appropriate data from the records of the Social Security Administration, Bureau of Labor Statistics, and Bureau of Employment Security for all out-of-scope industries was completed in 1962. Amendments adopted as the result of this review were incorporated in a supplement to the 1957 edition, published in 1963. The 1967 revision resulted from data from the 1963 Economic Census and the 1965-66 review of the 1957 edition as modified by the 1963 supplement. There were further revisions in in 1972 and in 1977.

On February 22, 1984, the Office of Management and Budget (OMB) published a Federal Register notice of intent to revise the Standard Industrial Classification for 1987. In response, businesses, trade associations, individuals, and Federal, State, and local government agencies submitted proposals for over 1100 individual changes. The last revision by the United States Government of the SIC was in 1987.

SIC Codes Today

In the official U.S. Government SIC Code system, there are a total of 1,514 codes (included in the 2-digit, 3-digit, and 4-digit levels). The U.S. Government specified in the SIC Code Manual that agencies could use additional subdivisions within specific four-digit industries to further break down industries. Private companies seized on this and created the 6, 7, and 8-digit SIC codes systems (known as Extended SIC Codes).  These Extended SIC Codes account for more specific sub-industries, as well as evolving the system for new and emerging industries.  Presently, the Extended SIC Codes total over 10,000 individual code classifications and are being continually updated. Researchers, data analysts, developers, marketing teams, and more use SIC codes for more specific targeting options than any other classification system available.