I know, that Switzerland and Liechtenstein are not members of EU. However, they are members of Schengen. Schengen rules remove all internal border controls between member countries.
If I travel to Switzerland, must I take my passport with me, or would it be enough to have my personal ID of one of EU countries?
Inside Schengen Area, I don't expect to be stopped for border control. But police can control a car anywhere, and possibly, this is where I might need passport instead of ID.
It depends on your citizenship. Generally, the official homepage states:
Foreign nationals require a valid and accepted travel document to enter Switzerland. In addition, a visa is required in certain cases. Furthermore, sufficient funds must be available or procurable by legal means to cover the cost of living during the transit through or the stay in Switzerland. The Swiss Federal Office for Migration (FOM), the Swiss foreign missions and the cantonal migration authorities will gladly provide information on the principal conditions for entry to Switzerland (www.bfm.admin.ch).
Now the question is, what is a valid travel document? This depends on the country. There is a long list of valid travel documents for each country. Assuming from your profile that you're Polish, a ID card is enough.
