The majority of US businesses are privately owned, which means that they do not sell stock to the public. They are not required to make detailed reports to the
Mergent Intellect has at least directory information on many private companies.
Forbes Largest Private Companies This list is updated every year and can be found at the Forbes website by clicking on LISTS and then clicking on “Private Companies.” This list offers minimal information about the companies, such as revenue for previous year, revenue change, net profit, and employees. Further information on these companies can be found in
Inc. Magazine’s 500:
U.S. Corporate Registries A listing by state of government agencies that oversee company registrations. From the U.K.'s Companies House.