Legal certainty is central to taxation decisions. This article describes the current legal situation and discussions in four Nordic countries. Sweden and Finland are specialized in dealing with taxation cases in administrative courts. In Denmark and Norway, no specialization exists in taxation cases. I maintain in this article that legal certainty would benefit from explicit signals from the state about the requirement of special knowledge and unbiasedness in authority and court decisions. These signals could well take the form of specialization in the courts. The need for specialized expertise is particularly extensive in tax law. It is also crucial for the agencies’ officials and judges to be aware that a subjective sense of unbiasedness in decision making does not necessarily mean that the unbiasedness aimed for has been attained. Self-awareness of this kind would ensure that argumentation and grounds for decisions would be made credible and transparent, to the benefit of legal certainty.