The history of Swedish Post Services start in the 17th century. Until the 20th century, smaler post offices were found in various small buildings around the old part of Stockholm. The last 'small' building that was used in that way, is now the Postmuseum (found in 6, Lilla Nygatan). It was modernised for the last time, back in 1820.
With the increase of postal quantities, the old building became insufficient, and a 'new' offices therefore was built at Rödbotorget (near today's Sheraton Hotel). The building was inaugurated in the mid 1870s. Altough in the beginning it was more towards the outbounds of the old Stockholm, with the construction of the Stockholm Central Station in 1871, the Post Office became welcentred in the new Stockholm. Before the end of the century, the building needed to be expanded and renovated again. The department's expert advisor, architect F. G. A. Dahl (1885–1927), studied modern post offices in Germany and Belgium and produced plans for a new post office on the site. In late 1897 the Swedish architect Boberg won a competition and redesigned the building once more.
The Post Office was inaugurated by King Oscar II on October 27, 1903. It was a modern building for its time; featuring electricity, 58 WC with rings in mahogany, and PO boxes, first introduced in Sweden here. However, long before the inauguration, the site selected for the project had proven insufficient, and in 1915 construction works was started for an enlargement on the remaining third of the block. The building was declared a historical monument (byggnadsminnesmärke) in 1935. A major rebuilding in 1976–78 was followed by several alterations during the 1980s. Three of the four courtyards were glazed-over in 1987–92 resulting in a galleria, a restoration of the central hall, and the addition of a superstructure creating space for 800 new work-rooms.
On the occasion of the inauguration of "Posthuset" (the post office), a 5 Kronor stamp was issued.
It remained valid until March 1, 1961.