Swiss migration law is governed primarily by the Federal Act of 16 December 2005 on Foreign Nationals (FNIA) and the ordinances regulating its implementation, the most important of which is the ASEO (a kind of “mini law” drafted under the auspices of the Federal Council).
The law is, however, subject to international agreements, the most important of which is the agreement concluded on 21 June 1999 between Switzerland and the EU on the Free Movement of Persons (AFMP).
Europeans who benefit from the AFMP are subject to a legal regime which can be referred to as preferential, exceptional or special. The AFMP should be considered as a package of additional rights. However, for those areas about which the AFMP is silent, the so-called general or ordinary regime of the FNIA applies.
The AFMP is an integral part of Swiss federal law. The agreement is complemented by the Federal Council ordinance entitled the Freedom of Movement Introduction Ordinance (FMIO).