In accordance with current Spanish regulations, an engineering project can only be carried out, and its work directed, by those who are in legal possession of the professional powers inherent to it. What, in many cases, is not fulfilled; especially by Technical Engineers who carry out projects exceeding the scope of their powers. Based on the analysis of the concept of "regulated profession" and those legally existing in Spain, the current ones, in the civil and military fields, of Spanish engineering are listed. Referring, for each of these, its current legal rules of attributions. It is concluded that, contrary to the socially widespread perception, Technical Engineering professionals exclusively have powers in the field of the legal specialty of their university studies. Perception due to the fact that the existing regulations until 2008 made it possible for Technical Engineering professionals to exercise the powers granted to the professions of Experts, which could exceed the scope of the specialty. Attributions of the Experts that, at present, cannot be exercised by the professional Technical Engineers, since, in 2008, the profession of Expert lost the status of regulated profession. What has recently endorsed the Supreme Court. Keywords: regulated professions; professional attributions; engineers; technical engineers