In this paper, the Constitutional Court uses the principle "tertium comparationis" in order to apply the principle of equality in the tax field to resolve a constitutional conflict that evolves a discriminatory tax rule that regulates a dependent worker as an independent professional. The judgment discusses additionally about other legal considerations, which not only tie to tax constitutional principles, such as the scope of functions of the legislator in the configuration of the tax system. Additionally, this paper exposes a later decision of a Court of Appeal about similar facts and rules.