A Greek word that came to Latin as *basis* derived, in our language, in the concept of **base**. Although it has several uses, in this case we are interested in keeping its meaning as the **foundation or foundation of something**.

**Taxable**, for its part, is an adjective that comes from the verb **impose**. The term qualifies what can **tax** with some kind of tribute or **tax**.

With these ideas clear, it is possible to advance in the definition of **tax base**. The expression is used in the field of **economy** to allude to the **quantity that expresses a certain economic capacity**, on which the payment of tax obligations is established.

It can be said that the tax base is a quantity derived from the act of measuring a **taxable event**. This last notion (taxable event) is used with respect to the circumstance or the **event** that generates a legal obligation to pay taxes.

The taxable event, in short, is that which originates a tax obligation: that is, the obligation to pay a **tribute** or tax. The economic capacity of people is manifested through these taxable events, but it needs to be valued (put into figures) in some way so that a tax can be applied. The tax base is this **valuation or magnitude** that is used in the tax to measure the economic capacity of the individual.

Take the case of taxes on **heritage**. These taxes are applied to the assets of a natural person, calculated from the value of their assets. The tax base is the **sum of monetary value** of these assets that constitute the patrimony of the subject.

**Methods of estimating the tax base**

First of all we have the **direct estimate**, a general method used to determine the tax base of most taxes in many **systems** tax. Generally, it is applied by the taxpayer himself when he presents his self-assessments.

One of the characteristics of this **process** is that between the tax base and its corresponding mediation there is a real correspondence, that is, it is a regime that seeks to bring the results closer to the true value of the elements that are calculated, in addition to taking into account with the same importance the data entered in the books and declarations of the taxpayer.

On the other hand is the **objective estimation**, a **method** of a voluntary nature that entails the resignation by the Administration and the taxpayer to measure the objective element in a real and direct way; instead, they apply data and indices from which an amount that represents the average tax base arises.

This method of estimating the tax base is dedicated to **small and medium enterprises**. The measurement of economic capacity is less related to reality, since the calculations are based on modules, signs and general coefficients that the Administration sets on an annual basis.

Finally we have the **indirect estimate**, an exceptional way of quantifying the tax base, by means of which the Administration has the power to determine this **fact** when you don’t have the information you need to do all the calculations accurately.

To be able to resort to indirect estimation, certain conditions must occur, such as that the person does not present their **statements**, that does it inaccurately or incompletely, that resists inspection, that obstructs its development, or that does not comply with its registration and accounting obligations. The means used to determine the tax base in this case are of the type *index*, that is to say that they derive from certain indications and not from well-defined data.