The Supreme Court recently held that although an officer cannot challenge a corporate assessment for which he/she is derivatively responsible on the basis of a substantive tax law error (e.g., delinquent corporation’s sales were exempt), the officer can challenge a corporate assessment on the basis it is procedurally defective. This is because the assessment is derivative in nature, allowing procedural delinquencies with respect to the corporate assessment to inure to the benefit of the officer. Otherwise, the officers’ due process rights may be violated to the extent the corporate assessment was not issued in accordance with the proper notice and an opportunity to be heard before becoming final. See Cruz v. Testa, 2015-Ohio-3292. In this case, the responsible officer established that the delinquent corporation was not properly served with several assessments, thereby invalidating both the corporate assessments and her resulting personal / derivative liability. Except for these types of procedural deficiencies, responsible persons are generally precluded from contesting the merits of the underlying liability. The only issue would be whether the person qualifies as a responsible corporate officer.