If you have all tenants under one lease, the tenancy ends only when all tenants give notice to terminate. There really isn’t a specific way to ensure that all the tenants leave at the end of the lease term. One suggestion is to ask them to provide you with the N9 notice 60 days prior to the lease expiring or have them all sign the N11- Agreement to Terminate a Tenancy form. If they all sign N9 or N11 and then one fails to move out, you would have to file an L3 Application with the Board to evict the remaining tenant(s). In the event that you cannot get all of them to sign the N9 or N11 and this one individual will not leave, legally there is nothing you can do to get him out at that point. However, since they were all under one lease they are all equally responsible for the rent, therefore if he stays and the rent is not paid in full you would then be able to give notice based on the non-payment of rent.