Built between 1761 and 1769 to house the Royal Customs House during the reign of Charles III, and designed by the famous Italian architect Francisco Sabatini, this monumental building located next to the Puerta del Sol, at the entrance to Calle de Alcalá, has been the headquarters of the Ministry of Finance since 1846.

Its original administrative function and purpose are clear from the rational distribution of its layout, based around three courtyards. Sabatini built a powerful yet simple facade, with a first stone-clad layer that transitions into a second layer combining brick and stone. Curved pediments are alternated with triangular ones, and under the eaves there is a frieze made up of several matching protrusions or modillions .

Inside you can find a library crowned by a steel and glass dome, added in 1963. It contains a catalogue of historical texts from the Central Library and the Central Archive, as well as a collection of historical-artistic photographs. As one might expect, it specialises in public finances, economics, and law.

In 1944, Miguel Durán Salgado was in charge of incorporating a new building that replaced the adjoining palace of the Marquis of Torrecilla, retaining the baroque facade attributed to Pedro de Ribera.