Hello. I gave my roommate a 30-day notice on November 14th. When I gave him my verbal notice he said to me, "So you will be out mid-December?" and I replied yes. I figured I would only have to pay 1/2 the month of December, but now he's asking for the full month's rent. I did not sign any type of lease and he told me upon move-in just to give him a 30-day notice. When I gave my notice my roommate never mentioned anything about paying the full month's rent and he's also advertising the room to be available for the 15th. I just want to know that since there is no lease, if I am right in being only willing to pay half the month. Thanks for your help.

In the absence of a lease, he can hold you responsible for the full month.

The providing of "notice" usually means it must be in writing... following up with a note and keeping a copy would have been your best insurance.