Amount on which the tax rate is applied. Taxable base
The tax base of the tax is the amount to which the rate must be applied, that is, it is the quantification or monetary valuation of the taxable event .
In general, the taxable base will be the amount of the consideration , defined as we will see below for each type of operation.
When the amount of the consideration is not known at the time of accrual the tax base must be provisionally fixed, applying sound criteria and subsequently rectified when the amount is known, if this amount does not coincide with the one provisionally fixed.