There are a lot of reasons that your credit may be in rough shape. Most are related to your spending habits. And, if you missed a few payments or your debt levels are too high—think over 30% of your total available credit limits—disputing errors won’t help you. You’ll have to make some changes to improve your credit scores instead. And you may have to wait a bit to see an uptick.
Credit scoring models usually take into account how much you owe compared to how much credit you have available, called your credit utilization rate or your balance-to-limit ratio. Basically it's the sum of all of your revolving debt (such as your credit card balances) divided by the total credit that is available to you (or the total of all your credit limits).