The tax authority is within what has become known as the rule of law, inspired by the basic principles of legality and equality Nevertheless, the administration, in its capacity as such, is endowed with certain privileges and guarantees to taxpayers. In some cases, such privileges are fully justified in view of its position to citizens (preferences in the collection of debts owed to other creditors, effectiveness and execution of administrative acts, etc.). However, in other cases, such privileges can put into question the alleged situation of equality between the Administration/ Contributors relationship, although it is true that, in many of them, the imbalance is the result of irregular functioning of the tax administration. Thus, without wishing to make a thorough analysis of the issue, the following "irregular" situations should be noted: a) The severe sanctioning regime “quasi sanctioning” is applied to the contributors who pay revenue later, facing the lightness and little diligence with which the Administration resolves the returning files as "improper revenue." b) The widespread practice of making payments on account, by an amount which usually exceeds the final tax liability, giving rise to late returns, with a clear financial loss to the taxpayer. c) The different quantification of interest on arrears, depending on who is the creditor; administration or the taxpayer. d) The delay in processing and the resolution of administrative records, with a systematic failure to comply with the deadlines specified in the laws, against the “irreparable” where the taxpayers derive the equivalent default. e) The practice of indiscriminate embargoes, lacking in due process f) The generalization of the so called “self-assessments” which requires the taxpayer to have a thorough understanding on the complex subject such as tax, against the rigorous, and why not say it, a high-handed “hindsight” act from administration. g) The exorbitant powers that the law grants the Administration to obtain information from third parties, often for tax matters without importance, and sometimes transgress the right to privacy. h) The existence of Economic and Administrative Courts, under the guise of the term "court" are integrated within the Ministry of Finance itself and must resolve the claims raised by taxpayers, prior to the judicial character. The systematic delay in the resolution of claims and the absence of real guarantees of impartiality, are an obstacle to immediate access to the courts, independent of the executive branch. i) The widespread practice of previous acts of inspection theoretically involves an interruption of the limitation period, which clearly violates a basic guarantee of the taxpayer. Ultimately, the complexity of the tax system and the operation at irregular times of the administration require they approach the tax reform in depth, which allows them to establish a framework of guarantees, taxpayer rights and obligations, at a reasonable level of equality, with the rights and guarantees of the administration. Such reform should, moreover, establish the appropriate means to correct the "irregularities" of the Administration in the management of taxes with the necessary efficiency.