The agency is responsible for the effective application of the national tax and customs systems and for those resources of other Public Administrations and the European Union whose management is entrusted to it by law or agreement.

It was set up as an autonomous agency attached to the former Ministry of Economy and Treasury through the former Secretariat of State for Finance and Budget.

As an autonomous agency, it has its own legal regulation different from that of the General State Administration, a regulation which, without detriment to the essential principles that must preside over every administrative performance, confers a certain autonomy to it in budgetary and personnel management issues.

It performs two lines of action to achieve this: on the one hand, the provision of information and assistance services for taxpayers in order to minimise the indirect costs associated with meeting tax obligations and, on the other, through the detection and correction of tax defaults through control actions.

With competencies throughout the national territory, there is the Central Delegation for Great Taxpayers (which are persons or companies which contribute a lot or with some specials taxes).