Several websites require payment to help you find a company's SIC code, but the NAICS Association website offers a free search tool that provides several pieces of information about companies, including their industry classifications. To complete the search, users must know the company's phone number, name and ZIP code, or name and full address.
A SIC code, or Standard Industrial Classification, is a number assigned to a company's industry. The numbers help government departments collect and analyze statistical data about businesses in the United States. Originally designed as a four-digit code in the late 1930s, the SIC code system is being replaced with the more modern, six-digit NAICS, or North American Industry Classification System.
To use the NAICS Association's search engine, users can visit their website and click on "Business Lookups." After choosing the type of information to search by, users can enter the information for the companies they are searching for.
Other search sites exist, although they aren't free. For example, the D&B Million Dollar Database claims to provide access to information on 34 million companies as of 2015 in return for a service subscription. The Lexis Nexis Database provides industry classification information to searchers, also for a paid subscription.