A credit score is a number that shows the amount of risk you are to a lender. It can range from 350 to 850—the higher the better. The easiest way to boost your credit score is to pay your bills on time. Jeannine Moore, Marketing Director for Consumer Credit Counseling Service of San Francisco, says the second most important thing you can do to improve the score is manage your credit balances in relation to your limits. About one-third of your score is based on what you currently owe lenders in relation to what you could possibly owe. Ms. Moore said she used to recommend not exceeding one-half of the available limit, but now things are tightening up even more and you should not exceed one-third of the limit. For example, if you have $10,000 of credit at your fingertips, you should keep the balance under $3,300 in order to raise your credit score.