You can serve the tenant with a notice of non-payment of rent anytime after the day the rent is due. The notice you would serve is a Form N4 which gives the tenant fourteen days to pay the rent owing. If the tenant does not pay within that time period then you would have to file an application with the Landlord and Tenant Board to obtain an eviction order. The entire process to evict for non-payment of rent can take approximately two months.