Are you asking if you can evict them despite this?Just to let you know that i will respond in the morning now.
Thanks for your patience.
When you say running costs, do you mean they pay you directly?
Yes, but do they pay you directly or the providers?
In that case, they are not paying rent. They are paying nothing that could be even considered rent.
Arguably they are just guests.
The reality though is that you couldn't just go round and evict them. They would get the benefit of the doubt and get an injunction to get back in.
But you can easily end this arrangement. I would recommend a S21 notice. You don't really need one but I would behave as though you do as then you are fully protected.
All you have to do is serve them notice in S21 form to evict them at the end of it though.
Can I clarify anything for you?