SIC and NAICS industry codes describe or define a company's business activities. These codes can also be very useful in business research, so make sure you keep track of them.
Standard Industrial Classification (SIC) was developed in the 1930's to classify companies according to primary business activity. Although it has not been updated since 1987, companies still use it, so it is likely that your company’s profile will include primary and secondary codes from both the SIC and NAICS manuals.
The North American Industrial Classification System (NAICS) – Since its inception in 1994, NAICS is the standard used by U.S. statistical agencies to classify business establishments for the purpose of collecting, analyzing, and publishing comparable statistical data related to the U.S. business economy.