How can I lose my German citizenship?
1) By voluntarily acquiring foreign citizenship:
If you willingly apply for foreign citizenship and obtain it, German citizenship is automatically lost. If you obtain foreign citizenship without an application for naturalization, you remain a German citizen.
Please note: Loss of citizenship can be avoided by obtaining a special permit ("Beibehaltungsgenehmigung") before you are naturalized in a foreign country.
2) Entering armed forces of a foreign country:
By voluntarily entering into the armed forces or other armed units of a country whose citizenship you also have (Example: a person with German and South African citizenship starts a career in the SANDF). German citizens can avoid loss of citizenship in this way by obtaining a special permit.
3) Renunciation (if you hold dual citizenship):
If you live in South Africa, possess South African (or another) citizenship in addition to German citizenship, and, for certain reasons, wish to renounce your German citizenship, you must file an application through the German Embassy Pretoria or (if you live in the Northern, Western or Eastern Cape) the Consulate General Cape Town.
Please include the documents cited in the application in the required form and have your signature certified. Your application will be forwarded by the German foreign mission to the German Federal Office of Administration in Cologne.
If renunciation is approved, a renunciation certificate will be issued to you. It will be turned over to you by the foreign mission. The renunciation does not enter into force until you accept the certificate.
4) By adoption:
If you are adopted by a non-German and are no longer considered to be legally related to your German parent(s), you lose German citizenship if the adoption automatically makes you a citizen of your adopted parents' country.