Do I have to tell my applicant that a hiring decision was made based on the background check?

Yes. Under the Fair Credit Reporting Act, you are required to inform your applicants that you are not hiring them because of information contained in the consumer report. You must inform your applicants of this no matter how small a part the consumer report played in your decision. You must also give your applicants a copy of the report and give them time to contest any inaccurate information in the report with the consumer-reporting agency that provided you with the report.