Old Telephone Exchange, Belgrade, Protected cultural monument in Kosovska Street, Belgrade, Serbia.

The Old Telephone Exchange at 47 Kosovska Street was designed by Branko Tanazević and completed in 1908 as Serbia's first purpose-built telephone exchange. Its asymmetrical facade has a shallow avant-corps at one end and large window openings; the corner is crowned by a dome. Shallow relief decoration draws on Moravian-school motifs such as rosettes, interlace and chessboard fields, combined with Secession elements.

The structure was built in 1908 as Serbia's first telephone exchange, marking the start of modern communications in the country. After World War I, an additional third floor was added to increase its capacity.

The facade carries shallow reliefs drawn from the Moravian school: rosettes, interlace, geometric patterns and chessboard fields, combined with Secession elements. The corner dome marks the building in the streetscape. It was featured on the 50,000,000-dinar banknote of 1993.

The building stands in a central Belgrade location and is easy to find, but it functions as a monument without public interior access. The best way to experience it is by observing the exterior during a walk through the old town area and appreciating the architectural details from the street.

In 1993 the building was reproduced on a 50,000,000-dinar banknote, a detail easy to miss when looking at the facade. The note dates from the period of hyperinflation, when such high denominations circulated in Serbia.