An industry classification system is a means of categorizing industries so that similar industries are grouped together and narrower industries appear within broader categories. Most company databases offer industry screening by classification system as well as by key words in the business description. Screening in a company database by use of an industrial classification system such as NAICS or SIC (see below can result in more comprehensive results than key word searching as many descriptions are incomplete or may be absent from a database.

On the other hand, industry classification systems do not keep up with the latest industry trends,  so new buzz words or ways of connecting related activities are not captured. For this reason a combination of approaches usually yields the best results

The resources listed below can be helpful in identifying the code to use for a company search by industry.

• Standard Industrial Classification System (SIC)
• Statistical Classification of Economic Activities in the European Community (NACE)
• North American Industry Classification System (NAICS)
• United Nations National Classifications: lists of classifications by country or classification category.