As of September 1, 2021, landlords can file an application for damages with the LTB within one year from the date the tenant was no longer in possession of the rental unit.The tenant must have moved out of the rental unit on or after September 1, 2021. However, in order to file this application with the LTB, you will have to find out their new residential address to be able to serve them. It is normal to get several estimates from qualified repair companies that can fix the damages in the rental unit.There is no way to force a tenant to return keys to you, so it is prudent to change the locks between tenants regardless.