Is your industry manufacturing, agriculture, retail, professional service...?
The North American Industry Classification System is used to organize industry information. It is a hierarchical classification system, offering five levels of detail.
Industries are represented by a six-digit number. The first two digits designate the economic sector: manufacturing, agriculture, wholesale, retail, professional services, etc. The subsequent digits designate subsectors and industry groups.
Each digit in the code is part of a series of progressively narrower categories.
Example:
44 - Retail
445 - Food & Beverage Stores
4452 - Specialty Food Stores
445291 - Baked Goods Stores
Thus the NAICS code for bakeries is 445291
The older Standard Industrial Classification (SIC) system may still be in use in some sources.
Government stats on industries are arranged by NAICS
Commercial publishers also use NAICS codes to organize industry info.