Systems and methods for identifying, evaluating, and accounting for effects of authorized user trade lines are disclosed. The systems and methods incorporate use of credit characteristics that describe the nature of authorized user trade lines on a credit file or across credit files, and the influence of those authorized user relationships relative to the non-authorized user trade lines on the credit file in the evaluation of credit risk. Systems and methods incorporating these credit characteristics can be used in identifying any bias in perceived credit risk, in the evaluation of credit risk, or other credit-related evaluation.