Hi there,
In Switzerland, taxes on lottery winnings are withheld at the source. That means the lottery company will keep a chunk of your money (35%) to cover taxes and pay out the rest. After you complete your tax return, you may get some of that money back, depending on the tax laws of your place of residence.
Because you pay taxes in the location you reside in at the end of the year, changing your place of residence to a canton with a low income tax rate may be beneficial. This is especially true if the win is very large, or if you have few binding attachments to your current place of residence.
If you are very mobile, moving to a country which charges little or no tax on lottery wins can save you even more - but only if the country in question has a tax agreement with Switzerland.
Best regards from Moneyguru