The Swiss authorities online
How you can lose citizenship and how you can regain it.
If you are no longer a Swiss citizen
you can apply to have your citizenship reinstated.
Loss of Swiss citizenship
You can loose your Swiss citizenship under various circumstances:
See the State Secretariat for Migration website for details.
Cantonal and communal regulations provide for the loss of cantonal and communal citizenship in certain cases (such as multiple citizenships). This is possible as long as your Swiss citizenship is not affected.