I don't know if anyone has come across this issue. I am in an owner occupied situation where I had a contract with a lodger where the rent (including bills) were paid monthly but they only had to give one week's notice in order to leave. They were only in the house for 4 months and have decided to move in with friends. The deposit was returned but now they are looking for part of December's rent as well. I don't know what the position is in such cases.