There is no inheritance tax on legacies from direct relatives in BL. When I received a significant inheritance, I just declared it on my tax return. It's about accounting where your sudden increase in wealth has come from, before they start asking questions.

Or you could do what a colleague of mine did. He opened a Swissquote account, put the money in there and used it to build a share portfolio - but neglected to tell the tax authorities about the account... :-O