Before assessing what to do with rent payments, you must first ensure that the notice you gave will be considered valid legal notice. From our correspondence, I still cannot determine if the property was sold to a buyer who expressly stated to you that they require the unit for their own personal use. If yes, then was an N12 served with a termination date falling on the end of a rental period? If rent is due on the first day of each month, then August 31st should be a valid termination date. If the tenant is leaving sooner than that on a minimum 10 day notice to the landlord (as their right as indicated on the N12 form), then the date they vacate would be the last day of the tenancy and the landlord may end up owing rent back to them on a per diem basis. If they vacate on July 31st, then the last month rent would be returned to them. On the other hand, the landlord may need to file an application for eviction (Form L2) with the Landlord and Tenant Board, if there is a chance that the tenant might not move out on or before the termination date on the N12. In that case, the L2 could be filed at any time or as late as 30 days after August 31st. An affidavit sworn by the purchaser (or their family member who requires the unit) should accompany the L2 application for termination.