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).
A good credit repair company first pulls your credit reports from each of the three major credit bureaus in order to pinpoint your credit issues. Why all three? Because each credit reporting agency has its own “data furnishers” (aka lenders, credit card companies, debt collectors, etc.), that report your credit information to them. And there may be errors that appear on one of your credit reports, but don’t appear on the others