The Agreement states that the Quota and the required compensations shall be determined initially and provisionally taking into account the sums stated in the State Budget approved for the corresponding tax year. Once the year is finished and the State Budget has been finally settled, the net quota set provisionally for the said year shall be regularized. The differences, positive or negative, which result after the regularization will be added to the provisional quota of the tax year after the one in which the regularization take place.
The final sum to be paid by the Autonomous Community of the Basque Country in each tax year shall be paid to the State Revenue Department in three equal instalments in the months of May, September and December of each year.
Finally the Economic Agreement regulates the effects on the provisional Quota of a variation in the assumed competences, whose annual cost at State level had been included in the charges of the State used as the basis for determining the provisional amount of the quota, so the annual cost shall be reduced proportionally to the portion of the year during which the Basque Country has assumed the said competences, with the quota being reduced accordingly.