This book describes the credit reporting infrastructure at the three largest nation-wide consumer reporting agencies (NCRAs), Equifax Information Services LLC, TransUnion LLC, and Experian Information Solutions Inc., with a special focus on the infrastructure and processes currently used by the NCRAs to collect, compile, and report information about consumers in the form of credit reports. Credit reports play an increasingly important role in the lives of American consumers. Most decisions to grant credit, including mortgage loans, auto loans, credit cards, and private student loans, include information contained in credit reports as part of the lending decision. These reports are also used in other spheres of decision making, including eligibility for rental housing, setting premiums for auto and homeowners insurance in some states, or determining whether to hire an applicant for a job. As the range and frequency of decisions that rely on credit reports have increased, so has the importance of assuring the accuracy of these reports.