A credit score is a numerical rating designed to measure and help predict the likelihood that a person will pay their bills late sometime in the future. A credit score is generated by a mathematical formula that looks at the way a person has paid the credit accounts contained in their credit report, and compares the payment history to millions of other people. Credit scores are not static. A credit score is based on the information that is contained in a credit file at the moment the score is requested. When something changes in the credit file the score changes to reflect the new information.