Who are the major credit reporting agencies?

Presently there are three major national credit reporting agencies operating in the United States maintaining records throughout the country. Each of the three, Equifax, Trans Union and Experian (formerly known as TRW) keep files on an estimated 150 to 170 million Americans. In addition to these three major credit reporting agencies there are also more than 800 smaller bureaus around the country that keep records only on consumers living withing their limited geographical areas. However, more than 500 of these 800 companies are either affiliated with or fully owned by one of the three major credit reporting companies.