The notice period of termination is one calendar month for the tenant and will always be counted to the end of the month following the termination month. For example, if you want your rental agreement to end at the end of March, you will need to send the notice of termination during February, at the latest.
The rental agreement can be terminated through the Tenant Pages or in person at the office. If a couple terminates their rental agreement, they both need to confirm it through the Tenant Pages or both have to go the the office to sign the notice of termination.