This monograph, is intended to be an approach into the proceeding of obligation determination per se, across a presentation of the substantial aspects that make up this process, the above, through the corresponding epistemological categorization of sources of obligation, as well, the corresponding mandatory regime, routed in clarifying the budgets and elements from which the tax burden is born for the taxpayer. On the other hand, the related proceeding component (terms of the procedural stages, mechanisms to notice, appeal) is exposed, this caused by the failures generated in the advocacy, regarding to persons that are bound by The Unit. This due to the lack of knowledge about proceed of determining obligations as such, mainly in connection to general terminology, the specific denomination of administrative acts that are uttered into the different stages of the procedure, as well, the noticing mechanisms and the most suitable way of being aware of The Unit proceeding.