Credit repair companies repair bad credit by using the Fair Credit Reporting Act to dispute negative items that are on your credit reports. This can be done by anyone, but has been mastered by some of the credit repair services at a large scale level. The slang term for this practice is dispute mill because they dispute lots of negative items on lots of credit reports, but it can still be quite effective if done right.
The FTC provides guidelines for credit repair as well as a sample dispute letter on their website (link below).
There are many strategies in resolving credit problems. Just make sure if you use a credit repair company, deal with a reputable company. Consider finding a consultant that is a member of a trade association that regulates the credit service industry. Credit Consultants Association is such an organization.
