Over the years, especially when interest rates on my mortgage were 16%, I've had 'lodgers'. Some remain lifelong friends. It was a commercial arrangement, they paid rent for a room and utilities with rules about everything from not inviting strangers on unannounced etc to which shelves in the fridge to use and never allowed smoking or drugs. Only one was a problem and I asked them to leave as they repeatedly forgot to lock doors and windows when they went out, they did understand my point and went on passable terms. Inland revenue has a Rent a Room scheme so you have to declare the rent but there's a generous allowance so unlikely to pay anything in tax, the house insurance and council tax may increase and possibly utilities. To avoid resentment I charged enough to cover a weekly cleaner. Back then it was fun, mostly students, or people working away from home and needing somewhere to stay just a few nights a week who went home at weekends. I would never have looked to any of them for friendship or companionship though and where that happened it was a bonus. Living with others can bring a clash of standards, mostly small things like cleaning the bath promptly so the next person can use it and putting the rubbish out. One girl only cleared her room out when there were no more cups or glasses left in the cupboard 😂 I'd be wary of an arrangement based on a need for company due to the pressure it puts on people but maybe an arrangement via Homeshare could work as expectations are aligned. There are nightmare tenants I'm sure but also a lot of lovely people out there needing accommodation for various reasons who could make lovely companions.