Switzerland is not a member of the European Union and so there is no free movement of goods between Switzerland and the EU meaning customs formalities and in some cases taxes and duties will be due on shipments to and from Switzerland.
Accordingly, the general rules and requirements for shipments to Switzerland are the same for all countries (EU or non-EU) with potential reductions in tariffs and quotas being applicable depending on the free trade agreement in place between the export country and Switzerland.
The guidance below is taken from the website of the Swiss customs authorities and is provided for guidance purposes. The material can be accessed directly here:
https://www.bazg.admin.ch/bazg/en/home/informationen-firmen/einfuhr-in-die-schweiz.html
It is strongly recommended to discuss the approach for shipments to Switzerland with your logistics team, shipping company and customs broker well in advance of making shipments.