- The rent brake applies to the rent agreed at the start of a tenancy.
- An addendum usually only amends the existing lease. In many cases, no new tenancy is created.
- If the addendum sets a new rent, current case law says the rent brake usually does not apply. This is true even when the tenants change completely.
- But: Not every addendum holds up in court. Often, your rent can still be reduced.
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Check my rent nowWhy an addendum makes such a difference
The rent brake applies when a new tenancy begins. Some landlords use an addendum to avoid exactly that.
Under Section 556d of the German Civil Code (BGB), in areas with a tight housing market the rent at the start of a tenancy may be no more than 10 percent above the local reference rent (ortsübliche Vergleichsmiete). So the key question is: Is a new lease being signed, or is the old one just being amended?
Lawyers distinguish between a novation (the old contract is cancelled and replaced by a new one) and a mere contract amendment. Courts only assume a novation if both sides clearly intended it. If an addendum states, for example, that the tenancy will be continued “with all rights and obligations” („mit allen Rechten und Pflichten fortgesetzt“), that speaks clearly against it. The date that counts is then the date of the original lease.
Addendum or new lease: the difference
| New lease | Addendum to the old lease | |
|---|---|---|
| Rent brake | Applies to the newly agreed rent | Only if the old lease was already covered or the court treats it as a new lease |
| Relevant date | Start of your lease | Start of the original lease, possibly years before you moved in |
| New rent | Must stay within the rent brake limit | Counts as a mutual amendment, so the rent brake usually does not apply |
| Deposit & notice periods | New deposit, periods start with the lease | Deposit is transferred, the previous tenancy period still counts |
So an addendum is not automatically bad, for example if the old lease was already covered by the rent brake and the rent stays the same. It becomes a problem if the old lease was signed before the rent brake was introduced or if the addendum sets a new, higher rent. According to a recent ruling by the Berlin Regional Court II (LG Berlin II), the latter applies even if the old lease was already covered by the rent brake.
The most common addendum tricks
We see these situations again and again. Some of them actually work for landlords, while courts have already ruled others to be an unlawful circumvention.
Taking over the old lease
You are moving in, but you do not get your own lease. Instead, an addendum lets you “step into” your predecessor’s lease. This is typical for shared flats (WGs), couples or replacement tenants.
Legal situation: The Berlin Regional Court II did not treat such a change of tenants by addendum as a new lease. Because the original lease was not covered by the rent brake, the new tenants could not rely on it (judgment of 28 July 2025, case no. 65 S 118/24).
Ask for the date of the old lease and request a new lease in your own name.
New tenant, new rent
Whether it is a flatmate swap, a replacement tenant or a couple: One person moves out, a new one moves in. And the same addendum contains a new, higher net cold rent (Nettokaltmiete), often with a new deposit. Yet the lease is supposed to “continue”.
Legal situation: The Berlin Regional Court II did not treat such a three-party addendum as a new lease, even though the tenant, the rent and the deposit were all changed. The rent brake did not apply (case no. 67 S 122/25). The Federal Court of Justice (BGH) takes a similar view when tenants agree to a higher rent during an existing tenancy (judgment of 28 September 2022, case no. VIII ZR 300/21).
Insist on a new lease. And keep a record of who suggested or demanded the addendum, for example by email. Whether it counts as an unlawful circumvention can depend on exactly that.
The surcharge shortly after moving in
The lease states a moderate rent. A second document, such as a “Nachtrag” (addendum), a “Bauoption” (building option) or an “Ausstattungsvereinbarung” (fittings agreement), then raises the rent a few weeks later, for example for new parquet flooring or a towel radiator.
Legal situation: Courts often treat the lease and the addendum as a single agreement made at the start of the tenancy. The rent brake then applies to the total rent (Berlin Regional Court, case nos. 66 S 45/18 and 63 S 166/22).
Good news: In these cases, the chances of a rent reduction are usually good. Have the total rent checked.
The “goodwill gesture”
Your landlord offers you a small rent reduction by addendum, unprompted. Sounds fair, but it can be costly if you are actually entitled to much more.
Legal situation: According to the Federal Court of Justice, a rent that is reduced by mutual agreement during an existing tenancy is no longer subject to the rent brake either (judgment of 17 December 2025, case no. VIII ZR 56/25). The rent is newly set as a result.
Before signing, have it checked how high your rent may legally be under the rent brake.
The inflated previous rent
Landlords may charge a new tenant the rent the previous tenant paid. That is why some raise the previous tenant’s rent by addendum shortly before they move out, so they can charge more afterwards.
Legal situation: Rent increases agreed in the last year before the previous tenancy ended are disregarded when determining the previous rent (Section 556e(1) sentence 2 BGB).
If your landlord relies on the previous rent, they must disclose it. CONNY requests this information for you.
Moving to another flat in the same building
You move to a larger flat in the same building. But your landlord handles this only through an addendum to your existing lease.
Legal situation: As a rule, this does not count as a novation but as an amendment of the existing lease. What matters then is the date of your original lease.
If your first lease was signed before the rent brake applied, insist on a new lease for the new flat.
The legal situation at a glance
Case law is not uniform. What matters is the wording of the addendum, how close it is in time to moving in, and whether the old lease was already covered by the rent brake. If the addendum was signed at the same time as the lease or shortly after, courts often treat both as a single agreement. In that case, the rent brake applies. If, on the other hand, an existing lease is continued by addendum, courts usually see it as a mere amendment.
The rule of thumb
If the original lease was already covered by the rent brake and the rent stays the same, you usually keep your rights even after an addendum. If the addendum sets a new rent, however, current Berlin case law says the rent brake generally does not apply, even when the tenants change completely.
The circumvention question is not fully settled
Courts do not rule out an unlawful circumvention of the rent brake in principle. But they want to know how the addendum came about: Who suggested or required it? Was the flat previously advertised at a higher rent? The better these circumstances are documented, the easier it is to show a circumvention.
What you should do now
Whether you are moving in or already living in the flat, these steps protect your claims:
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Do not sign under time pressure
Take the addendum home and read it carefully. Look out for wording such as „tritt in den Mietvertrag ein“ (enters into the lease) or „wird fortgesetzt“ (is continued).
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Ask for the date of the old lease
When was the original lease signed? If it was before the rent brake was introduced in your city, be careful.
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Ask for a new lease
When tenants change, a new lease in your name is the cleaner solution. Do not accept a higher rent by addendum during an existing tenancy.
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Document the circumstances
Keep the listing, emails and messages. They should show who wanted an addendum instead of a new lease and what rent was originally asked for.
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Have your rent checked
Check on our website, free and without obligation, whether your rent is above the legal limit.
Already signed?
That does not automatically mean you are out of luck. Whether the rent brake applies depends on the wording of the addendum, the old lease, the timing and how the addendum came about. We check your case free of charge and without risk.
How to enforce your rights with CONNY
CONNY is the leading consumer rights platform and stands up for tenants’ rights. We check your lease including any addenda, request the necessary information from your landlord and aim for an amicable agreement. If that fails, we take your case to court and cover all lawyer and court fees.
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Note: This page provides general information on the legal situation in Germany (as of September 2026) and does not replace individual legal advice. The rulings mentioned are decisions on individual cases.