Under this law, the bank was established as a privileged institution (for the next 25 years in the form of a joint stock company), with an initial capital of 20 million dinars, and it was envisaged that its activities would be conducted under the control of the state.

Between 1922 and 1925, the bank building was extended to cater for its space requirements, to fill the entire area of the city block, in the form of an irregular pentagon.

[2] Jovanović's immediate models were Palazzo Farnese in Rome, designed by Antonio da Sangallo the Younger and Michelangelo (1513, and 1534–46), and Semper's mid-19th-century Oppenheim Palace in Dresden.

The heavy and monolithic rustication of the basement and ground-floor zone, tempered by the regular rhythm of arch-headed windows, is a clear reference to the Florentine 15th-century palazzo.

The artistically rich design of interior spaces includes a large number of functional and decorative arts and crafts objects, which form an integral part of the architecture of the building.

Being accessible to the public, these spaces were elaborately decorated in the neo-Renaissance style, with a composition pattern based on contrasts between full and empty surfaces, and calm monochrome and vibrant polychrome details, on the generous use of floral ornamentation, and on the alternation of different materials.

The general impression of luxury and monumentality of the interior is reinforced by an ensemble of decorative wall painting, one of the best preserved and most prestigious created in the early 20th century.

The symbolism of the decoration, through the motifs of cornucopias, sphinxes, gryphons and, the central one, Mercury, clearly refers to the function of the building, conveying the idea of success, affluence and prosperity.

To be singled out in terms of artistic merit is the allegorical bust of Serbia, a work of the sculptor Đorđe Jovanović originally intended for the monument to the heroes of the Battle of Kosovo in Kruševac.