Letterbox of the PTT
Chur, as of 1948
In 1849 the Swiss state took over the entire postal system, which had previously been the responsibility of the cantonal, regional and private postal services. In 1850 standardisation of transportation prices was achieved through the introduction of postage stamps issued by the Swiss Confederation. In contrast to later ones, the first letterboxes were of different shapes and colours.
In 1920 the telephone and telegraph services were integrated into the postal service. Subsequently, the agency was renamed «PTT» (post, telegraph and telephone). Ever since 1939, the colour yellow has been the trademark of the Swiss Post. After having previously only been used for postal stagecoaches and «Postautos» [postbuses], the letterboxes were now also painted in the «postal yellow».