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Professor Walter's Classes: Industry Information

Industry Classification System Basics

A large portion of the information available on U.S. industries and businesses is organized by two major industry classification systems: the North American Industry Classification System (NAICS) and the Standard Industry Classification System (SIC).  Both are hierarchical, numerical classification systems.  Internationally-focused sources often apply other industry classification systems.

Companies involved in a wide range of activities may have multiple industry classifications, although usually one industry is considered primary.

The classification systems themselves do not provide direct links to industry information but many online databases and print directories enable searching by these codes. These systems also provide useful descriptions of industries and sub-industries as well as inspiration for search terms.

Major Industry Classification Systems

  • North American Industry Classification System (NAICS)

    Pronounced ‘nakes’, 6-digit classification system focusing on business activities and production processes. Developed jointly by the U.S., Canada, and Mexico to provide comparable business statistics throughout North America.  Businesses using similar production processes are grouped together.

  • Standard Industry Classification System(SIC)
    4-digit classification system focusing on manufactured goods and their constituent materials.  Developed in the 1930s by the U.S. Central Statistical Board, superseded by NAICS and has not updated since 1987, although many sources still reference it.

    • Databases for Industry Information

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