Question: What is the SIC code and how do I get one?
Answer: Standard Industrial Classification (SIC) codes are four digit numerical codes assigned by the U.S. government to business establishments to identify the primary business of the establishment. Industrial Classification codes were developed by the Federal Government in conjunction with the U.S. business community during the 1930's. They've proven to be a useful tool for professionals looking to segment domestic markets, analyze customer relationships, and conduct general business research. SIC Codes divide all major economic activity into ten major divisions. The first two digits describe the nature of this activity in very general terms (i.e. Mining, Construction, Manufacturing). Remaining digits break down these categories into specific products and "sub-industries." If more than one SIC Code is assigned to a company, the first one listed is the primary line of business. The remaining codes, if any, comprise at least 10 percent of the firm's annual revenue.
United States Department of Labor