The ReferenceUSA database contains detailed information on more than 14 million U.S. businesses, 1.5 million Canadian businesses , and 210 million U.S. residents.

Business information is compiled from the following public sources: more than 5,600 Yellow Page and Business White Page telephone directories; annual reports, 10-Ks and other SEC information; Continuing Medical Education (CME) directories; federal, state, provincial and municipal government data; Chamber of Commerce information; leading business magazines, trade publications, newsletters, major newspapers, industry and specialty directories; and postal service information, including both U.S. and Canadian National Change of Address updates.

250 employees make telephone calls to verify the information on each business and health care provider in the database. 17 million phone calls are made each year, and businesses with 100 or more employees are phone-verified at least twice a year.

ReferenceUSA's residential information is compiled from more than 3,900 White Page telephone directories. Each listing appears in the database exactly as it appears in the phone book. ReferenceUSA does not include unlisted phone numbers, Direct Marketing Association and Canadian Marketing Association suppression files, or state-regulated mail and telephone suppression files (U.S. data only). Information is available eight to 12 weeks after it appears in the phone book, and the file is processed through U.S. and Canadian National Change of Address records on a monthly basis.

Each U.S. residential listing also contains information from the most recent U.S. census, including median household income, median home value, latitude/longitude and percentage of owner-occupied housing.