In general for citizenship through naturalisation, you have to have lived legally in Switzerland for at least 10 years and hold a permanent resident permit (C permit). Foreign nationals acquiring Dutch citizenship, or Dutch nationals acquiring a foreign one, need to give up their citizenship of origin, except in some specific circumstances – for example, for those acquiring their spouse’s or partner’s citizenship or those holding an asylum residence permit. For citizens from these countries the residency requirement to apply for naturalisation is 2 years, but for other nationalities it is 10 years.