The length of your credit history—also called credit age—is an important factor in your credit score. Lenders prefer borrowers with longer, well-established histories of responsible credit use. This metric includes the age of your oldest account, your newest account, and the average age of all your credit lines. Keeping old accounts open and in good standing can help improve this portion of your score. So yes, credit history age definitely affects your score—it is not excluded from the calculation.