Maybe you know that the national credit bureaus –Experian, Equifax and TransUnion – assign scores based on your creditworthiness. Maybe you didn’t know how they come up with that score. If you don’t, chances are your credit score is roller-coastering, and probably more down than up. The precise formula for FICO scoring remains a well-kept credit-bureau secret, it is known that payment history is biggest component of the scoring system. Late payments are lethal; miss paying a mortgage, car or card payment on time, and your score can take a triple-digit dip. Thus, the most direct route to credit repair involves making payments on time. An even more obvious way to repair credit: stop applying for credit. An apparent easy solution is applying for another credit card or loan. But: every time someone checks your credit and runs an inquiry, your score will take a hit. Likewise, those who charge up plastic, then receive a higher limit from the credit card are digging a new hole as they try to fill up and old one. The good news is that a FICO score doesn’t discriminate against age, sex or ethnicity. Bad news: people who don’t think before they ask for money will pay the penalty in a declining credit-bureau score. Until they find credit repair.