Get back
what you're owed.

You may have been overpaying rent on your apartment for years. RentReducer calculates your claim under Swiss federal law and sends the letter via Swiss Post Priority Mail (A-Post). If your landlord stays silent or refuses, the app guides you all the way to the conciliation authority. The first tenants already pay less rent thanks to the app.

Download on the App Store Get it on Google Play

Claim check + rate alert freeLetter from CHF 9.90Priority Mail (A-Post) delivery includedNo subscription

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App Store

Google Play

Swiss FADP/nDSG compliant Data stays on your device Swiss made

13:12

RentReducer

Your claim

CHF 73 per month

CHF 876 per year · from June 1

Create letter →

Recalculate

Rent history

Current CHF 1'920

New (from Jun 1) CHF 1'847

Reference rate 1.25 %

Data and law from official Swiss sources

Federal Office for Housing Federal Statistical Office Tenancy law (CO + VMWG) Zurich rent calculator

Press

In the media

Tsüri.ch 16 Jun 2026

Diese App soll Mieter:innen helfen, weniger Miete zu zahlen

View the story

Tele 1 12 Jun 2026

Steht mir eine Mietzinsreduktion zu? Zentralschweizer App soll helfen

View the story

More coverage coming soon.

How it works

Three steps from claim to ready-to-mail letter.

Enter your current rent and the date of the last adjustment. The app calculates the claim, generates the reduction request with your signature and hands it to Swiss Post. If your landlord stays silent or refuses, the app handles the next step too.

Check your claim

Enter your rent and the date of the last adjustment. The app calculates under federal law (Art. 270a CO + VMWG art. 13) including inflation and cost increases. 1:1 with the rent calculator of the Zurich courts.

≈ 2 min · free

One tap to send

The app generates your reduction request with your finger-signature, hands it off encrypted to our Swiss postal partner, and mails it as a standard letter or registered. You get a push confirmation.

≈ 3 sec · from CHF 9.90

Auto-reminders and follow-ups

If your landlord doesn't reply, the app reminds you after 30 and 60 days. Depending on their answer it suggests the right follow-up letter: a reminder letter for silence, a request for explanation and evidence for refusal, or a conciliation petition as the last step.

automatic

Why we built this

Swiss tenants miss out on millions every year.

Only a fraction of those entitled actually claim. The effort puts people off: calculating the claim, drafting the letter, scheduling reminders, chasing silence or refusal with the next step. RentReducer takes those steps over completely, from the initial claim to the conciliation authority. And it works: the first tenants are already paying less rent.

88 %

of tenants don't claim a reduction

Only 12 % actively ask for a reduction, even though about half are entitled. Source: ZKB study 2026.

CHF 876

average annual saving

For a typical 2.5-room flat at CHF 1'920. The letter is a one-off CHF 9.90 to 29.90, the saving comes back every year.

2 min

from open to ready-to-send

You enter your rent and the adjustment date, the app handles everything else through to the push confirmation that the letter is in the mail.

What sets RentReducer apart

Private. Precise. With one tap.

What sets RentReducer apart from a Word template.

Court-grade calculation

RentReducer uses federal source data (BWO reference rate, BFS national CPI) and reproduces the official Zurich-courts rent calculator down to the cent. Including inflation, cost increases and an affordability check.

Privacy-first

Your data stays encrypted on your device. No account, no cloud DB. Only the finished PDF is handed encrypted to our Swiss postal partner.

Free rate alert

Push notification when the Swiss reference rate drops. No sign-up, no subscription. You can use the app purely as an early-warning system, that's perfectly fine too.

Case-by-case guidance

Each apartment gets its own case: current claim, every letter sent, status per landlord response (accepted, partial, refused). Reminders at 30 and 60 days, concrete suggestions for the next step. Closed cases move to the archive, a new one starts any time.

From request to conciliation

Four letter types in the app: reduction request, reminder letter, request for explanation and evidence, conciliation petition. Each follow-up is prepared in the case context, with all prior letter copies attached. For the conciliation letter you upload the lease directly from the app, by photo, file or built-in document scanner.

Built for your situation

Living alone, with a partner, or in a shared flat? Each tenant signs on the device, the letter is worded in the right form automatically. If a company manages your flat, the app pulls the address from the Swiss commercial register. For private landlords you just type the name.

13:12

RentReducer

Active case

Reduction request mailed

Sent · May 5, 2026 · Day 12

How did they reply?

Accepted Partial Rejected No reply

✉

Reduction request

Sent on May 5, 2026

Suggested

Reminder letter in 18 days

We'll ping you automatically.

Case tracking

RentReducer thinks ahead.

After the letter goes out, the app shows you the case status. Mark your landlord's response with one tap, and the app suggests the next step: reminder letter for silence, request for explanation and evidence on refusal, conciliation petition as last resort.

If nothing happens, the app pings you on day 30 and 60. No calendar reminders to set, no templates to research. Closed cases move to the archive, a new one starts whenever you want.

Price

No subscription. Less than 1/3 of your first month's saving.

The claim check is free. You pay only when you mail the letter, and even then only once per letter.

Free

CHF 0

unlimited use

Check your claim in 2 minutes
Rate alert when the reference rate drops
Rent history + savings counter
Data locally encrypted, no account needed

Perfect to dip in. If you have no claim to a rent reduction, you don't pay anything.

Popular

Letter mailing

CHF 9.90 to 29.90

once per letter · Priority Mail (A-Post) delivery included

Reduction request as a legally compliant PDF
Print + Priority Mail (A-Post) delivery by Swiss postal partner
Your own finger-signature, captured in the wizard
Auto-reminders + follow-up letters available

Add-ons (optional, à la carte):

Registered with tracking+ CHF 7.90

Follow-up reminder / document request (via Pingen, repeatable)CHF 6.90

Follow-up conciliation petition as registered mail with lease photo and prior letters attached (or Word download)CHF 6.90 + 7.90

The letter price scales with your monthly saving, about a third.

Save little, pay little. Save more, pay a touch more, but never above CHF 29.90.

CHF 9.90 / 14.90 / 19.90 / 24.90 / 27.90 / 29.90, depending on how much you save.

Frequently asked

What you'd want to know before you start.

Do I even have a claim?

If your last rent adjustment was based on a higher reference rate than today's, then yes, most likely. RentReducer calculates this automatically under Art. 270a CO and VMWG art. 13. You just enter your current rent and the date of the last adjustment.

The claim check itself is free. If your claim is zero, you don't pay anything, the calculation stays free.

What does the app actually cost?

The app is free. Claim check and rate alert stay free. You only pay for mailing the letter: a one-time CHF 9.90 to 29.90 depending on your monthly saving. Included: letter generation, print and Priority Mail (A-Post) delivery by our Swiss postal partner.

Optional: Registered with tracking (+ CHF 7.90). Follow-up letters at CHF 6.90 each, the reminder letter and request for explanation and evidence go out automatically via Pingen. The conciliation petition also goes from the app, as registered mail (+ CHF 7.90) with your uploaded lease photo and all prior letter copies attached. Prefer to mail it yourself? You can also download it as a Word file.

Is RentReducer an official government app?

No. RentReducer is an independent app and is not affiliated with, operated by, or endorsed by the Swiss Confederation, any canton, public authority or court. All official data and legal references come from official Swiss sources. See the Sources block below.

RentReducer does not replace legal advice. For legal questions, contact a cantonal tenants' association or a lawyer.

Can my landlord terminate my lease because I submit a rent reduction request?

No, you are legally protected. A termination as a reaction to a rent reduction request is voidable under Art. 271a para. 1 lit. a Swiss Code of Obligations (CO) (so-called retaliatory termination). The burden of proof lies with the landlord: they must demonstrate that the termination is NOT motivated by your request. In practice, landlords rarely succeed. The conciliation authority then declares such a termination invalid.

Additional protection: For three years from the conclusion of a conciliation or court procedure, your landlord cannot ordinarily terminate the lease (Art. 271a para. 1 lit. e CO). A termination at an inopportune time (during or shortly after an ongoing procedure) is also invalid (Art. 271a para. 1 lit. d CO).

A rent reduction request is a normal legal procedure and an everyday part of Swiss tenancy. If you still receive a termination: you have 30 days from receipt to challenge it before the conciliation authority (Art. 273 CO). Contact the tenants' association in your canton immediately (mieterverband.ch). The app FAQ contains a detailed step-by-step guide.

What happens with my data?

Your rent and contract data stays encrypted on your device. We operate no cloud database and you don't need an account. Only the finished PDF of your letter is handed encrypted to our Swiss postal partner so it can be printed and delivered.

Details are in the Privacy Policy.

How accurate is the calculation?

Cent-accurate against the rent calculator of the Zurich courts. We use the official data sources (BWO reference rate, BFS CPI) and reproduce the formula from VMWG art. 13 including inflation, cost increases and an affordability check.

When the federal data is updated upstream, the app picks it up automatically and recalculates with the new values on next open.

What if my landlord doesn't reply?

RentReducer reminds you automatically after 30 and 60 days. At every reminder you can fire the right follow-up letter with one tap, by status: reminder letter, request for explanation and evidence, or conciliation petition. Each follow-up letter costs CHF 6.90. The reminder letter and request for explanation go via Pingen with letter delivery included. The conciliation petition also goes straight from the app as registered mail (+ CHF 7.90) with your uploaded lease photo and prior letter copies attached, or you can download it as a Word file and mail it yourself.

If you go to conciliation, the app helps you with the directory of the cantonal conciliation authority (source: BWO).

What devices does RentReducer run on?

iPhone (iOS 15+) and Android (9+). Works on phones and tablets, the larger tablet screen just gives you more room to type.

All 41 questions about RentReducer →

Sources and disclaimer

All from official Swiss sources.

RentReducer links directly to the underlying federal data and legal references. You can verify every value in the app yourself.

BWO Mortgage reference interest rate Federal Office for Housing, primary data source (German) BFS National Consumer Price Index Federal Statistical Office, for the inflation component CO Tenancy law: CO art. 269 ff., esp. 270a Swiss Code of Obligations (Fedlex) VMWG Ordinance on residential and commercial premises VMWG art. 13, calculation formula SB Conciliation authorities directory BWO, cantonal addresses (German) ZH Tenancy law information from the Zurich courts Verification reference (in German)

RentReducer is an independent app. It is not affiliated with, operated by, or endorsed by the Swiss Confederation, any canton, public authority or court, and it does not represent any government entity.

The app is not legal advice and does not replace an attorney. For legal questions, contact a cantonal tenants' association or a lawyer.

Ready to claim what's yours?

The claim check is free. The letter starts at CHF 9.90 including print and Priority Mail (A-Post) delivery. If your landlord stays silent or refuses, RentReducer guides you all the way to the conciliation authority.