Mieter Schreiben an Vermieter
You just got a Mieterhöhung, the landlord raised the Nebenkosten without paperwork, or the Kaution from your old flat has been sitting in a stranger's account for eight months. You want a letter that holds up in front of a judge if it comes to that, without spending 180 euros on a first-consult lawyer.
This guide walks through the five parts a legally sound Mieterschreiben needs under German law. We built the Mieter App because we had this same problem ourselves in 2023, and the mechanical parts are easy enough to handle without paying for help.
1. What a valid Mieterschreiben must contain
Under §556 BGB and §557 BGB the letter has to do four things at a minimum. It names the parties. It references the Mietvertrag. It states the factual basis for the demand. It states a Frist by which the landlord has to respond.
Skip any of those and the letter is not a formal Aufforderung, it is just a complaint. A complaint does not restart the Frist clock and does not preserve evidence if the matter ends up in Amtsgericht later.
2. Write the header
Most people get this wrong. The header needs:
- Your full name and current address
- The landlord's full name or Firma as it appears in the Mietvertrag
- The date in TT.MM.YYYY format
- A reference line naming the Mietvertrag and flat address
- A Betreff line under twelve words
A real header looks like this:
Max Mustermann
Beispielstr. 12
10115 Berlin
Frau Eva Vermieter
Vermieterweg 4
10435 Berlin
Berlin, 24.04.2026
Betreff: Mieterhöhung vom 01.03.2026 — Widerspruch
Mietvertrag vom 01.06.2021, Wohnung Beispielstr. 12, 10115 Berlin, 2. OG links
3. State the facts
One paragraph, three to six sentences. Say what happened, when, and how you know. If you have dates and witnesses, name them. If you have photos of mold or a Betriebskostenabrechnung, reference them in the letter and attach them as Anlagen.
Do not argue law yet. Do not make demands yet. Just record what the situation is. Every sentence in this paragraph should name either a date, an amount, or a person.
4. State the demand and the Frist
Use "fordere" or "widerspreche" depending on whether you are making a demand or rejecting one. Then state the deadline.
A reasonable Frist in most rental disputes is 14 days from receipt. For Nebenkostenabrechnung disputes the statute gives you 12 months under §556 Abs. 3 BGB, but the landlord has no statutory response deadline, so you set one in your letter.
Example phrasing: "Ich fordere Sie auf, bis zum 08.05.2026 eine korrigierte Nebenkostenabrechnung zu übersenden. Sollte die Frist ergebnislos verstreichen, behalte ich mir rechtliche Schritte vor."
The Mieter App, which we ship on Android and iOS, generates this paragraph automatically with the correct §BGB citation for your case, saving a lookup trip through the Mieterbund guides.
5. Sign, send, and keep the evidence
Print two copies. Sign both in pen. Date both with the same date as the Betreff. Send one copy via Einschreiben mit Rückschein through Deutsche Post. Keep the other copy, the Einlieferungsbeleg, and the Rückschein when it comes back.
Einschreiben mit Rückschein costs 5.65 euros at the Schalter and gives you evidentiary proof of delivery accepted by every Amtsgericht in Germany. Email does not. Without the Rückschein the landlord can claim the letter was never received, and you cannot prove otherwise.
FAQ
Do I need a lawyer for a Mieterhöhung dispute?
Not for the first letter. A well-written Mieterschreiben is enough to start the clock and preserve your options. If the landlord takes the matter to Amtsgericht, a Fachanwalt für Mietrecht is worth the 180 to 300 euro consultation.
What happens if the Frist passes without a response?
The landlord has accepted neither your facts nor your demand. You then decide: escalate to Amtsgericht (Kostenrisiko roughly 600 to 1,200 euros on a 2,000 euro claim), or drop it. A second reminder is usually not useful.
Can I send a Mieterschreiben by email?
Only as an informal first signal. Email does not preserve evidence and does not count for statutory Fristen. Always follow up by Einschreiben within three days.
What if my landlord is a Hausverwaltung?
Address the letter to the Hausverwaltung and CC the Eigentümer if you have their address. Either party counts as Vermieter under §164 BGB, but CC'ing the Eigentümer raises the attention level noticeably.
Source: Deutscher Mieterbund, §556 BGB, §557 BGB, Bundesgesetzblatt, 2025.
The mechanical parts take 30 minutes end to end.