The final definition of the current Swiss national boundary was decided at the Vienna Convention in 1815, along with all the other European boundaries.
The course of the boundary has undergone significant changes since the then because of various construction projects (airport in Geneva-Cointrin, customs stations in Chiasso and Bardonnex, dams in Livigno, Emosson and Lei, etc.). Since no nation has the right to annex territory of another nation, these modifications always resulted in the exchange of equally sized territories.
Because the boundary is a constituent of the national sovereignty, any modification in its course must be affirmed by parliament and is thus subject to the facultative referendum.
The technical upkeep of the boundary – exact definition of the course, monumentation of the markers and their maintenance – was delegated to the Federal Office of Topography and includes the entire documentation. Article 22 of the Geoinformation Act (GeoIG) provides the legal basis for this process.
At swisstopo, the responsibility of the national boundary is organized in the process Geodetic Control Points, which is part of the Geodesy Division.
For each neighboring country there is a commission consisting of representatives of swisstopo, the Federal Department for Foreign Affairs (EDA), the Federal Customs Administration (EZV) and the geometers of the respective cantons. These commissions are responsible for all matters pertaining to the definition of the course of the boundaries.