The different evaluation criteria that sow our taxation system and auditing values

The tax map consists of a set of taxes and contributions that form watertight compartments, so that the criteria and ratings that are the basis for a tax are not applicable to others.

This rule, justifiable in certain cases, can lead to a situation of legal uncertainty for taxpayers, especially considering that, in most cases it is the taxpayer who must interpret the tax rules in order to self-assess their taxes.

This problem is particularly evident in the various assets and rights of taxpayers. In the different taxes that make up our tax system we find, for example, with the following evaluation criteria, in many cases applied to the same assets:

a) Market value.
b) Acquisition value.
c) Compensation
d) Declared value.
e) Cadastral value (for property).
f) Value checked by the Administration.
g) Fiscal Value.
h) Value of capitalization.
i) True worth
j) Actual acquisition value.
k) Value for the purposes of inheritance tax and donations.

This diversity of values, probably justifiable from the perspective of the tax technique produces widespread insecurity in taxpayers. Of course, it is not well understood how the town hall can turn a receipt for Property Tax, which sets a value of 10,532,200 pesetas, while the taxpayer is forced to enter in their tax return and Heritage Capital Transfer the price paid for housing (22,300,000 pesetas) and, eventually, the Administration can check whether or not the value is the "real" (?) to propose, in turn, further value.

There is, of course, blame towards the administration for such an ambiguous and equivocal situation, whose sole mission is to apply the laws passed by Parliament. It is, however, the legislator who is responsible to clarify the tax situation, providing the necessary transparency and legal certainty to the system.

On the contrary, we should attribute the administration the discretion and lack of rigor with which sometimes develops the powers of checking values. On countless occasions, the values reported to taxpayers, resulted from the actions of verification carried out by administration, and lack sufficient necessary motivation to enable that confirm the reality of such assessments.
Sometimes, such motivation is absent; others, merely to refer to indexes and average values.

Courts have noted that the valuation given by an expert of the administration "must contain not just a figure that reflects the result, but the evidence or calculation that has been taken into account to reach the result reflected". In another sense, they have pointed out that the assessment "is not legal if the motivation is limited to record the expression of mean values in the area."

The taxpayer, in addition to the lack of motivation of the evaluations drawn by the Administration has at its disposal the possibility to request an "expert appraisal" if it considers that the proven value does not match the real.