Credit repair companies have experience in repairing bad credit. They know and have the skills necessary for the job. They know what to do to improve your credit score. They also know how to use consumer protection laws to defend your rights. They also know what to do if creditors substantiate facts in your credit report. All this experience comes in handy when they are working to improve your credit score. If you were working on it by yourself, you would have to learn all of this information.