UK Sole Trader, working for UK company, but resident overseas

I'm about to start a consultancy business serving 1 customer (although possibly 2 or 3) who is based in the UK. I am a UK citizen, with a UK NI number, but I am resident in Greece, and will likely become a Greek tax resident in 2025 at some point (based on >183 days a year living in Greece). Is registering as a sole trader the best (in fact is it allowed?) option, and would I be able to get a UK zero tax code under a dual taxation agreement with Greece when I become a tax resident here? Is there anyway I can remain a UK taxpayer only? I am also likely to be turning over >£90,000 so I belive will need to register for VAT. Would that have a bearing on my tax status?

Hi,
This forum is for general queries only and is intended to help you self-serve.We are unable to provide specific advice tailored to individual circumstances. 
You may wish to contact our Self Assessment team for advice.
Self Assessment: general enquiries 
Alternatively ypu may wish to seek professional advice.
Thank you.