A complaint about the use of a rented flat reaches you. One message mentions unauthorised activity, another only speaks of frequent visitors. You are considering a warning letter (Abmahnung). Before a letter is drafted, handling requires a clear set of facts and a definable objective.
Keep observation and legal assessment separate
First gather concrete details: What was observed, when and where? Who can describe their own observation? Which statement is merely hearsay? A repeatedly used buzzword does not thereby become independent evidence.
Ask about the connection to the actual tenancy agreement and the agreed use. Frequent visits, a single noisy incident and another alleged use are not automatically the same breach of duty. This article does not decide any of these constellations categorically. If the basis is unclear, it is first examined what can be demanded at all.
Formulate the desired outcome
Our editorial recommendation: Internally describe the concrete condition to be restored or the specific behaviour to be stopped. If no one can say what the tenant would actually have to change, the case is not yet prepared for a clear request for remedial action.
This includes existing permits and agreements. A previously confirmed use should not be treated as if it had always been unauthorised without examination. Likewise, an unconfirmed complaint will not be entered into the file as a finally determined contractual breach.
Consider cessation and termination as different routes
Section 541 BGB provides for an injunction (Unterlassungsklage) if a contractual misuse continues despite a warning. [UNTERLASSUNG] This can be a different aim than the termination of the entire tenancy.
For an extraordinary immediate termination § 543 requires an important reason taking into account the individual case and the interests of both parties. In the case of a breach of duty paragraph 3 generally names an unsuccessful reasonable remedy period or unsuccessful warning as well as statutory exceptions. [ABHILFE] A warning is therefore not a general preliminary stage that entitles termination automatically after any number of warnings.
Have the appropriate course and required content reviewed by an expert. This contribution does not provide a blanket model sentence, a fixed number of warnings or a period suitable for every case.
Fictitious case: The allegation is still too vague
Jasmin hears that a business is being run in a flat. The first message contains neither concrete activities nor time. On enquiry it concerns several people who carried packages one evening. The landlady notes the actual details and has their significance for the contract examined.
She does not immediately use the heading Gewerbliche Zweckentfremdung in a threatening letter. Only when the facts, contractual reference and, if applicable, the public-law question are clarified will it be decided what reaction is required. A possibly justified allegation is thereby not ignored but made examinable.
After a request, follow the actual course of events
If an expert-appropriate letter has been sent, secure its content and service. Then check what actually happened afterwards. An old incident is not counted as a new continuation just because the same complaint was forwarded again.
For a persistent problem the expert support receives the newly evidenced status. A successful remedy is also recorded. Your result is a factually reasoned, appropriate conflict handling. It can carry a clear request and, if necessary, further legal steps, without turning an unclear complaint into an already proven ground for termination.