Under the German nationality law citizenship is granted under the principles of ius sanguinis and ius soli. Citizenship is granted under the ius sanguinis principle if at least one of the parents is a German citizen, or under the ius soli principle if born in Germany to foreign nationals residing in Germany with an unlimited permission to stay and a regular stay for at least 8 years. German citizenship can also be granted through naturalisation as a rule following 8 years of residency in Germany, but non-EU and non-Swiss citizens must usually renounce their previous citizenship before being naturalised in Germany.
According to German Law, prior to acquiring another citizenship, a German citizen has to obtain permission from the German Authorities, otherwise the German citizenship will be lost. An administrative fine is also applicable for non-registration or denial of a second citizenship.
The loss in citizenship does not apply in case of a German citizen acquires a second citizenship of an EU member state, Switzerland or a state with which the German government has signed a treaty.
There are a number of special circumstances or conditions under which Germany allows dual citizenship: