Hi All
As has been said elsewhere on the forum the tax treatment of 2nd & 3rd pillar lump sum withdrawal when leaving Switzerland depends on the Double Tax Agreement between the destination country and CH.
It could be helpful to capture the knowledge about each country in one place and this thread has the most obvious title. I will go first
UK: per the DTA the 2 & 3 pillar payout is not taxable in the UK
https://www.englishforum.ch/finance-banking-taxation/279375-uk-tax-swiss-pension-withdrawal-2.html
Conclusion: if you withdraw your 2 or 3 pillar after moving to UK there is no tax due in the UK. You do however need to pay the source tax in Switzerland. The rate depends on the canton where your 2nd pillar institution is with Schwyz being the lowest.
I am really interested to know how it works in Spain if anyone knows