A Kündigungsausschluss or Kündigungsverzicht (both: no-termination period) means that a rental agreement cannot be terminated for a certain period of time. The rental agreement states how long this period lasts. After that, the tenant or landlord can terminate the agreement by giving notice. This period can last up to four years. However, if there is a serious problem, such as a large amount of unpaid rent, the agreement may still be terminated immediately without notice.