I am currently renting a commercial property on a month to month basis commercial lease and have just paid the current rates due. I sent an email today to the owner stating I would be vacating and she has approached me in the office and threatened me she is going to charge me for last years rates that she forgot about. Do I have to pay these rates (considering they are for last year and she forgot about them and has never hit me up for payment before I gave her notice to vacate)?