A bad credit score is a measure of a person's creditworthiness, based on their credit history. It is used by lenders, such as banks and credit card companies, to determine whether to extend credit or not, and at what terms. A bad credit score can range from 300 to 850, with anything below 600 considered bad. Improving a bad credit score will take time and discipline, but it is possible. The first step is to obtain a free copy of your credit report from one of the three major credit bureaus. Review the report for errors and dispute any inaccurate information. After that is done, pay all bills on time and pay down any existing debt. Additionally, limit applications for new credit and if possible, try to increase your credit limit on existing accounts. Finally, consider speaking with a qualified financial advisor about ways to improve your credit score.