I am retiring to UK after spending almost 20 years in Switzerland and having built-up a substantial pension pot through my employer's scheme.

I understand that the entire pension pot can be withdrawn once I stop being Swiss tax resident, but I will pay Swiss withholding tax on the amount. The rate of withholding tax depends upon the Canton where the pension scheme is located.

The advice from the accountants is that the UK-CH double taxation agreement means that the benefit is only taxable in Switzerland, so there is no UK tax to pay. However, they tell me that the situation isn't entirely clear so I need to get specific advice on my particular case.

Has anyone any experience of drawing-down a Swiss Pension whilst being a UK tax resident? Are there any particular tests that need to be satisfied to get UK tax exemption? For example, does the pension scheme need to be recognised by HMRC? Does it need to contain only pension funds earned in Switzerland?

Any help gratefully received.

The issue is if this was 'disguised remuneration', if you lived & worked in CH throughout & not in the UK this won't be an issue.
The legislation is more recent than 20 years, I looked into this 7 years ago, it only effects pension payments after the legislation, earlier payments are ring fenced.

The pension fund itself is not an issue, HMRC does not 'recognise' any Swiss pensions, no reason why they would.