Company A: a software development startup. Incorporated in Finland.
Person B: An UK resident and citizen
A is looking to employ B to work entirely remotely. Because of reasons, it is not possible to have B be a contractor of any sorts, hire him through an UK company or to set up a new company in UK for the sole purpose of employing him.
Based on limited research on Finnish law this is not a problem, i.e. B just handles the taxes and employee fees himself. UK side is a complete mystery, i.e.:
Is this even possible a) while UK is an EU member b) after a no-deal brexit
Are there any tax mines/double taxation issues a) while UK is an EU member b) after a no-deal brexit
How would the logistics of this work, i.e. how exactly does B fulfill his obligations to UK tax authorities