Becoming non-resident is the first step
You remain UK tax resident until you break residence under the Statutory Residence Test. The test counts your UK days and ties such as family, accommodation and work; a Swiss residence permit or home does not change the answer by itself. If you leave part-way through a tax year, split-year treatment can tax you as UK resident only up to departure, provided you meet one of the statutory cases, most commonly starting full-time work overseas or ceasing to have a UK home. Tell HMRC when you go: file form P85 if you do not complete a Self Assessment return, or claim through the SA109 residence pages of your departure-year return if you do.
What the UK keeps taxing
Non-residence narrows the UK's claim to UK-source items; it does not switch it off. UK rental profits remain taxable through the Non-Resident Landlord Scheme, and gains on UK residential property must be reported and paid within 60 days of completion. UK government-service pensions generally stay UK-taxable, while the UK-Switzerland treaty usually gives Switzerland the right to tax private, occupational and UK State pensions paid to a Swiss resident. If you return within 5 years, the temporary non-residence rule can also bring gains on assets you owned before leaving, plus certain pension drawdown and close-company distributions, back into UK tax in your year of return.
Switzerland taxes you too
A genuine move does not make you tax-free. Switzerland taxes residents at federal, cantonal and communal level, levies a wealth tax at cantonal and communal level on worldwide net assets, and some cantons offer expenditure-based lump-sum taxation to non-employed new arrivals. The overall burden depends heavily on your canton and commune, so confirm the local rules with a Swiss adviser before you commit. Our moving to Switzerland guide covers both sides of the move in detail.