Internal credit ratings are expected to gain in importance because of their potential use for determining regulatory capital adequacy and banks’ increasing focus on the risk-return profile in commercial lending. Therefore, the components of internal credit ratings merit not only a qualitative but also a quantitative analysis. Whereas the eligibility of financial factors as inputs for credit ratings is widely accepted, the role of non-financial factors remains ambiguous. Analysing credit file data from four major German banks we find evidence that the combined use of financial and non-financial factors leads to a more accurate prediction of current and future default events than the single use of each of these factors respectively.