The credit score that haunts your dreams at night and can awaken you in a cold sweat is based largely on the history of your financial life. The three major credit bureaus (Experian, TransUnion and Equifax) have their own version of the FICO score, based on the mathematical model Fair Isaac refined in the late 1970s. Each of the credit bureaus' scoring systems is slightly different, which can result in different scores for a single person. As a result, lenders generally use the middle score for reference.
Credit scores are based on your payment history, how much outstanding debt you have, the length of your credit history, what type of credit you've received and the frequency with which you fill out new credit applications. The factors that have the most bearing are payment history and outstanding debt, which account for 35 and 30 percent of your score, respectively. By the way, the average American score is 692.
