Your credit file is a dossier assembled by private companies, sold to strangers, and used to decide whether you get a loan, an apartment, an insurance rate, or a job. This article explains who may look at that file, what the companies must do when the information in it is wrong, and why the dispute has to go to the bureau rather than to the creditor. It covers the reinvestigation process and its thirty-day clock, the separate obligations of the furnishers who supply the data, and the remedies available when the process fails. It explains identity theft from the victim's side, including the identity theft report, blocking, fraud alerts, and security freezes, and why a freeze is the strongest and least used protection available. Examples follow one consumer through a mixed file, a fraudulent account, and a denied mortgage. Readers finish knowing exactly what to send, to whom, and what happens if nothing is fixed.