The Swedish post services dates back to the 17th century, and its headquarters were during the first 300 years found in various small buildings in Stockholm Old Town.

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.

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.

[2] Boberg favoured a kind of orientalism combined with a sense appropriateness in an era when such decorations and exotic styles were regarded as lacking Swedish recognition (sakna hemortsrätt).

The plastered walls, originally intended to be dressed in stone, are covered with postal emblems; the coats of arms of the nation, its provinces, and the city; and a pine-cone border characteristic for its time.

[1] Boberg's use of ornamentation accumulated criticism which described it as to naturalistic and falling short of monumentality — "almost as modelled in clay rather than carved in sandstone".