The PTT Archive is situated in Köniz near Bern and is classified as an object of national interest in the Swiss Inventory of Cultural Assets.

[3] This is the earliest known historical source that is concerned with the creation of an archive and a library for the then still autonomous directorate General of Posts.

There are also documents about various postbus routes, transport and correspondence statistics, records about the development of the telephone and telegraph networks in Switzerland, the introduction of NATEL (Nationales Autotelefon), the internet and telefax, documents about PTT's research and development department, and employee records.

The archive also holds several hundred linear meters of grey literature, from workplace regulations and forms to telephone books.

The PTT Archive holds the only complete collection of Swiss telephone books, dating back to the very first edition, issued in 1880.

The PTT's former academic library with a focus on the history of postal services and telecommunication is also part of the holdings.

With the interviews of former employees, the PTT Archive can establish a reference with today's Swiss Post Ltd. and Swisscom Ltd.

Apprentices engage with historical sources and discuss their current work routine with former PTT employees.