Hi Giorgio,
It’s a good question - the combination of Brexit and Covid has seen a rise of remote working from our clients. I’ve just spoken to our Technical Services Manager Michael Awuye, who has replied:
Your question combines immigration law and self-employment. We cannot advise on the former but in respect of your self-employment, there is no requirement to be physically in the UK to be self-employed. So you could be overseas and registered as self-employed and be required to file a Self Assessment in the UK. "
Hope this is helpful!