Is the Mietpreisbremse worth pursuing in your case? Find out how much you could potentially save and what to look for when comparing the costs of Conny and other legal tech services.
If you discover that your rent may violate Germany's Mietpreisbremse (rent brake), two questions quickly arise: How much money could I actually save – and what is the best way to enforce my rights?
The second question matters more than it might seem at first. In addition to lawyers and tenants' associations, there are now various legal tech services that offer to enforce Mietpreisbremse claims without tenants having to bear their own cost risk. In many cases, a fee is only charged if the claim is successfully enforced.
That sounds straightforward. But the business models can differ considerably. So the important question is not only whether the Mietpreisbremse is worth it, but also how much of the financial benefit actually remains with you after the costs of enforcement.
How Much Can You Save with the Mietpreisbremse?
The financial value of a successful rent reduction is often underestimated. Many tenants initially think only about getting back rent they have already overpaid.
In reality, there can be three separate financial benefits:
- repayment of rent already overpaid,
- further repayments for the period until the rent is actually reduced,
- future savings from permanently paying a lower rent.
The last of these can actually account for the largest part of the overall financial benefit .
Example: Your Rent Is €250 Too High
Suppose you are paying €250 more per month than legally permitted under the Mietpreisbremse. If you can reclaim 30 months of overpaid rent, that amounts to €250 × 30 months = €7,500.
However, your rent will usually not be reduced on the same day you first assert your claim. If, for example, another six months pass before the rent is actually reduced, this adds a further €250 × 6 months = €1,500.
That already brings the potential repayment to €9,000.
The long-term effect can be even greater. If you remain in the apartment for another five years after the rent reduction, you would save €250 × 12 months × 5 years = €15,000.
In this example, the total financial benefit would therefore be €7,500 + €1,500 + €15,000 = €24,000.
So a rent reduction of "only" €250 per month can make a difference of tens of thousands of euros over time.
Does That Mean the Mietpreisbremse Is Always Worth It?
Not necessarily. The amount by which your rent could be reduced is only one of several factors.
What matters is how much rent can actually be reclaimed, how long you expect to remain in the apartment, whether any legal exceptions apply and what it will cost to enforce your rights.
That is why it makes sense to look not only at your chances of success, but also at the enforcement model you choose.
How Much Do Conny and Other Legal Tech Services Cost?
Legal tech services have made it considerably easier for many tenants to enforce the Mietpreisbremse. Depending on the provider, tenants can pursue their claims in return for a success-based fee rather than financing legal proceedings themselves.
The basic promise often sounds similar: If the claim is unsuccessful, you bear no or only limited cost risk. If it succeeds, the provider receives a fee.
However, the way this fee is calculated can differ significantly.
For example, one provider may charge a percentage of the rent recovered from the landlord. Other pricing models may also include part of your future rent savings. There can also be important differences in which out-of-court and court services are included and who bears the financial risk if litigation becomes necessary.
So it is not enough simply to ask:
"What percentage is the success fee?"
The more important financial question is:
"How much of my total financial benefit will actually remain with me?"
What Does the So-Called "Conny Judgment" Have to Do with This?
This question has now also become the subject of court proceedings.
In a judgment dated 24 November 2025 (case no. 113 C 5049/25), the Berlin-Mitte Local Court held an assignment of Mietpreisbremse claims to the legal tech company Conny to be void as contrary to public policy. The court considered there to be a particularly striking imbalance between the agreed success fee and the service provided.
However, the judgment does notmean that Conny's business model or success-based legal tech services are generally unlawful. The decision is legally controversial, and other courts may assess the issue differently.
For tenants, another aspect of the case is particularly interesting: it draws attention to the actual price of successfully enforcing a claim.
If a Mietpreisbremse claim generates a financial benefit of €10,000, €20,000 or even €30,000 over time, the exact structure of the success fee can make a substantial difference.
Conny, Legal Tech, Lawyer or Tenants' Association: What Should You Compare?
A low price alone does not necessarily make an offer better. Conversely, a higher success fee is not automatically uneconomical if, for example, the provider assumes a substantial financial risk on your behalf.
When comparing different options, tenants should therefore consider five questions:
- What is the total fee if the claim succeeds?
- Does the fee apply only to repayments or also to future rent savings?
- Which services are included?
- Who pays the costs if court proceedings become necessary?
- How much of the total financial benefit ultimately remains with me?
The last question is particularly useful when comparing different offers.
Why Cost Risk Still Matters
The lowest success fee is of little help if you have to assume a substantial litigation risk yourself.
Anyone who brings a court case and loses completely will generally have to bear court fees, their own legal costs and, where applicable, the recoverable legal costs of the opposing party.
There are different ways of covering this risk. Legal expenses insurance may cover statutory legal costs. Some tenants' associations also offer legal protection. Depending on your circumstances, legal aid may be available. There are also legal tech and litigation funding models under which a third party assumes the financial risk of pursuing the claim.
This is why price and risk should always be considered together.
When Is the Mietpreisbremse Worth It for Me?
Ultimately, the question can be approached with a relatively simple calculation.
Compare the potential financial benefit of reducing your rent with the costs and risks involved in enforcing your rights.
The greater your monthly rent overpayment, the more rent you can reclaim and the longer you expect to remain in your apartment, the greater the financial value of a successful rent reduction can become.
When choosing a provider, you should therefore not focus only on claims such as "free", "no upfront costs" or "you only pay if we succeed". What matters is what you receive in return for the agreed fee – and how much of your rent savings ultimately remains yours.
Check Your Rent for Free
Would you like to know whether your rent may be too high and how much you could potentially save?
With RentAid, you can first check whether the Mietpreisbremse may apply to your case, how high your potential savings are and whether you have a claim to repayment of rent you have already overpaid. The check is free of charge.