I have a hostile lodger in my personal residence (In California) and don't have a written agreement/lease. He occupied the home as of late February. I gave him 30 days written notice on the door to the bedroom he is renting, sent him the notice through the USPS, and emailed the notice to him. He paid his rent on time (within the first 5 days of the month) and always paid his portion of the utilities as agreed. In the notice I sent to him, I stated, "If you elect to vacate the premises prior to that date (which is July 14, 2010), any rent and utilities will be pro-rated to the date of vacancy." I never collected a security deposit. If he leaves prior to June 30 and the utility bills have not arrived, can I hold the unused portion of the rent until I prorate the utility bills as agreed and then give him a refund? Or, do I prorate the rent, refund the unused portion, and ask him to cover his portion of utilities as agreed after he leaves? Also, if he stays after June 30 and doesn't pay rent, what are my rights?