Hi 4getmenot,
No matter what you think. It is best if he provided for every bill half share between you and him. Property, service, property maintenance, food etc etc. Log all payments he makes to you. It would be better if he paid it directly into you account for records purposes. All you need to do is let him pay a sum you think is sufficient fo the months expenditure and sundry expense in advance. In this case, if he upped and went you do not have to take him to a small claims court. It is like him renting a place of his own except you are not profited. But nevertheless the Tax Man allow you to rent-a-room of an allowance of �4250 if you also live in the property you own.