Moving abroad - income in the UK from a business - taxation UK or Foreign?

Disjoint

Hi all - I am moving abroad (tomorrow) and starting a job in Switzerland on Monday. Little fun fact: I have not met a single person from the company, all interviews were on the phone and video chat. The company I will be working for is quarantining me when I land so I will be WFH at a new job where I never met anyone in person. The new normal of working life! I think it's pretty cool how company are adapting, especially as I really needed this job (went on self employment this year thus got no support from the government when it all went to hell with Covid).
My wife has a small business in the UK (property management) it earns about £12k a year and she also has some property income. When she moves to Switzerland with me in July I'd be interested to hear how that income will be treated. Will the Swiss authorities tax it, or will the UK authorities tax it? I understand that the property income is very straight forward and gets taxed in the UK and then declared back to Switzerland but with a dual taxation treaty there is nothing that needs to be paid in Switzerland. I've always done my wife's taxes and my own taxes so would like to keep doing so - but this might prove trickier than I thought so wanted to gauge the difficulty before deciding to engage the services of someone more competent than me.
I have started to do some research on the subject and have started looking at it, but there is a lot of conflicting advice out there. 

martindow

Although Switzerland is not in the EU it has a lot of agreements with the EU possibly including reciprocal taxation agreements.  Who knows what will happen from next year but the current situation could change.