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Additional costs, rent increase, or rent –
is that actually correct?

Upload your statement or enter your address – Renthelfer checks it with AI and shows you in minutes where you can save money or defend yourself. Understand and respond to letters from your landlord in seconds.

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How it works
Or start directly:
Rent increase & potentialLocation check
DIN 5008 · GDPR
3 reports, 3 questions

Each question – a clear answer in minutes

No waiting: you enter your documents or your address, Renthelfer checks them with AI and gives you an orientation.

No matter which side you're on

active

Tenant

Understand letters from your landlord, respond correctly, and don't miss anything important.

A reply in minutes
  • Understand letter from landlord
  • Prepare appropriate response
  • Check utility bills for errors
  • Don't miss deadlines
  • Send letter officially
Start as Tenant

Landlord

Create correctly formulated letters, respond to tenants, and keep everything organized.

In minutes instead of hours
  • Create the right letter
  • Respond correctly to tenants
  • Structure documents
  • Manage listings & inquiries
  • Send letter officially
Start as Landlord

From Question to Complete Answer

Four steps, one continuous path – from unclear writing to sent letter.

01

Letter Scanner

Understand What's Inside

Upload a photo or PDF – you receive a simple explanation and an assessment of your options.

Open
02

AI Letters

Receive a Suitable Response

Renthelfer suggests a completed letter template for you to customize, supported by AI.

Open
03

Utility Cost Check

Check for Overpayment

Upload your statement – Renthelfer highlights potential errors and irregularities for guidance.

Open
04

Paper Letter Dispatch

Send Officially

Send as a letter or registered mail with a click – no printer, no trip to the post office.

Open

And afterwards: all documents saved, deadlines in view.

Start for free now

Renthelfer is an AI-supported self-help tool providing guidance, information, and templates – not legal advice. For complex cases, consult a lawyer or the tenants' association.

New: handover protocol

Record the condition of the flat, with photos that count later

At move-in and move-out: document rooms, defects, meter readings and keys, and have it countersigned by link. The other party needs no account.

Move-outMove-inMove-inMove-out

Drag the slider to compare

Example image

Mould in the corner of the room: not there at move-in, clearly visible at move-out.

  • Photos for every room

    Floor, wall, ceiling, window and door with a photo and description, straight from your phone.

  • Meters and keys

    Electricity, gas and water with a photo, plus the number of keys handed over.

  • Countersign by link

    The other party signs on a phone or computer, no account and no app.

  • Comparison at move-out

    Move-in and move-out side by side: photos with a slider, meter consumption, keys and a deadline reminder.

Create a protocol

The protocol documents the condition and is not legal advice.

Marketplace

Commission-free to your next home

Browse commission-free rental listings — free of charge and without signing up.

Browse listings

What an AI letter looks like

DIN 5008 compliant · personal · legally clean

Sender

Lisa Schmidt

Beispielstraße 12

10115 Berlin

Recipient

Hausverwaltung Müller GmbH

Hauptstraße 45

10117 Berlin

Berlin, 2 November 2026

Request to keep a cat

Dear Sir or Madam,

I would like to adopt a quiet indoor cat and am asking whether you agree to a cat being kept in the flat.

Of course, I will make sure the cat is well looked after and that neither the neighbours nor the flat are disturbed or damaged.

I am happy to tell you more and to answer any questions. Please let me have your reply in writing by 16 November 2026.

Kind regards

Lisa Schmidt

DIN 5008 AI-generated ~30 sec

Generated in under 30 seconds — no templates, no manual tweaks

Create your own letter

What our readers say

Experiences from our users.

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Simple pricing

Start free. Upgrade when you are ready.

01

Check

Utility costs, rent increase, location — enter your details. The analysis runs instantly.

free
02

See the result

Traffic-light verdict, rough savings, deadline — you know right away if it's worth a next step.

free
03

Get the document

Once, for this exact case — or with a subscription, for every case ahead.

one-time or subscription
Check

Free

  • Additional costs, rent increase, and location checks included
  • Result, dispute value, and deadline immediately visible
  • Renthelfer AI Assistant and rent index map included
  • See deadlines in your results, documents and templates
  • Apartment search, wishlist, and application profile
  • Publish listings
Start for free
Single Document
19,90 €
  • The complete result of your check
  • The appropriate letter according to DIN 5008
  • No recurring payment
  • 30-day City-Pass: further reports for this city automatically free
Purchase once

Need more than one check? The subscription is cheaper.

Renthelfer Tenant✦ Popular
€9.90/month
  • Access full results
  • Nebenkosten & rent-increase checks: fair use up to 30/month
  • Save deadlines with e-mail reminders
  • Objection and deficiency letters according to DIN 5008
  • In 11 languages; the German original is authoritative
  • Everything from Check
Start tenant subscription

No VAT is charged under § 19 UStG. No credit card required.

Renthelfer in Comparison

Faster and cheaper than traditional methods — for the first step.

Recommended€9,90/month

Renthelfer

Safe & affordable

Time per letter

Renthelferfrom a few minutes
Lawyer1–2 days
Templates30–60 minutes
Self30–60 minutes

Cost

Renthelfer€9,90/month
Lawyer€150–€300+
Templates€19–€49
SelfFree

AI support

Renthelfer
Lawyer
Templates
Self

Available anytime

Renthelfer
Lawyer
Templates
Self

DIN 5008 Standard

Renthelfer
Lawyer
Templates
Self

Multilingual

Renthelfer
Lawyer
Templates
Self

Focus on rental topics

Renthelfer
Lawyer
Templates
Self

Mail delivery

Renthelfer
Lawyer
Templates
Self

Data protection

Renthelfer
Lawyer
Templates
Self

Intelligent. Secure. Efficient.

Renthelfer combines AI technology with a clear structure — for ready-made letters in seconds.

Frequently asked questions

Answers to the most common questions

F.01

Is Renthelfer legal advice?

No. We provide drafting help and AI-powered letter generation. For complex disputes we recommend a lawyer specialised in rental law.

F.02

How safe is my data?

Your data is stored on servers of ServerDiscounter in Germany (data centers in Stuttgart, according to the operator) and encrypted in transit; selected content is additionally stored in encrypted form. Backups are stored encrypted with Backblaze in the EU. For AI features we use OpenAI as a data processor — your data is not used to train AI models. Details are in our privacy policy.

F.03

Does this really work without a lawyer?

For most standard matters — yes. Defect notices, rent reductions, payment reminders and terminations follow clear wording our AI handles well. For very complex cases a lawyer may make sense.

F.04

Can I edit the letter before sending?

Yes. Every generated letter is fully editable. You can adjust, add or shorten text before downloading the PDF or sending it.

F.05

Which languages does Renthelfer support?

Letters are always generated in the German standard (DIN 5008); the German version is authoritative. Translations for you personally are available in 10+ languages.

F.06

Can I cancel anytime?

Yes. Monthly plans can be cancelled at the end of the month, yearly plans at the end of the term. No fine print, no hidden fees.

F.07

What is the City-Pass?

Once you've paid for a Location Check or Market & Location Analysis for a city, further reports for that same city are automatically free for 30 days — no repurchase needed.

Still have questions? Just start for free.

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