Generality of the duty to contribute

We know that every group, every community, has common needs that must be funded through the financial contributions of its members. The State is the way in which a community of citizens organizes itself politically. Therefore, the State has the right to demand, and citizens have the duty to provide, the necessary financial resources to finance common needs.

Taxes, therefore, are sums of money that citizens are required by law to pay so that the State and other public administrations have sufficient resources to finance public spending. Article 133 of the Spanish Constitution states that: "The original power to establish taxes corresponds exclusively to the State, through law. The Autonomous Communities and Local Corporations may establish and demand taxes, in accordance with the Constitution and the laws."

Article 31 of the Spanish Constitution states that: "Everyone will contribute to the maintenance of public expenditures according to their economic capacity through a fair tax system inspired by the principles of equality and progressivity that, in no case, will have a confiscatory scope" .

This article means that, in our country, the contributions citizens must make to help pay for public expenses must be governed by a very important principle: financial capacity. Therefore, although all citizens have to contribute ( principle of generality ), they do not always do so in the same proportion because not everyone has the same economic resources. The principle of equality determines that citizens with equal economic capacity must pay the same amount of taxes and that citizens with different economic capacities must pay different amounts of taxes. Thus, the Constitution determines that, in the Spanish tax system, those who have more money must contribute more euros to the common fund for the payment of public goods and services ( principle of progressivity ). Although with certain limits, because the Constitution also requires that the tax system not take the application of the principle of progressivity so far that, through taxes, it could threaten the economic capacity of taxpayers ( confiscatory scope ).