Mietpreisbremse: What Landlords Must Know When Re-Letting (2026)

What is the Mietpreisbremse?

The Mietpreisbremse (rent cap on re-letting) limits how high you may set the rent when you re-let a unit. In an area that the federal state has designated as a strained housing market, the new rent may exceed the ortsübliche Vergleichsmiete (local comparative rent) by no more than 10% (§ 556d(1) BGB). That is the central limit against which every re-letting must be measured.

The rule is set out in §§ 556d to 556g BGB. It applies only to existing residential housing in the designated areas and, following the Bundestag's extension, runs until 31 December 2029.

How high may the new rent be?

What counts is the ortsübliche Vergleichsmiete for a comparable unit by location, size, fittings, type and year of construction. You normally determine this from the local Mietspiegel (rent index). To that figure you may add 10%.

For example: if the ortsübliche Vergleichsmiete is 9.50 €/m², you may charge at most 10.45 €/m². For a 70 m² flat that is a maximum of roughly 731.50 € net cold rent. Going above this without a valid exception risks a tenant objection and reclaims.

What exceptions apply?

There are three situations in which you may exceed the 10% limit. You must actively rely on each one before the contract is signed.

Exception	Legal basis	What is permitted
Higher Vormiete (prior rent)	§ 556e BGB	If the last owed Vormiete was already higher, you may continue to charge it (but not a rent that was itself impermissibly inflated in the meantime).
Neubau (new build)	§ 556f BGB	Units first used and let after 1 Oct 2014 are entirely exempt.
Comprehensive Modernisierung	§ 556f BGB	If the unit was comprehensively modernised, the cap does not apply to the first letting afterwards.

Important: An exception only helps you if you inform the tenant, unprompted and in text form, of the exception ground before they make their contractual declaration (§ 556g(1a) BGB). If you fail to provide the disclosure, you may demand the higher rent only two years after providing it later — until then the capped rent applies.

What disclosure duty do you have?

If you rely on an exception, § 556g(1a) BGB requires pre-contractual disclosure in text form. You must tell the tenant which exception ground you are relying on:

• for the Vormiete (prior rent), its amount (you need not reveal the previous tenant's identity),
• for a Neubau, that the unit was first used and let after 1 Oct 2014,
• for a Modernisierung, that and to what extent it was comprehensively modernised.

In addition, after the tenancy begins the tenant may request further information about the basis of the exception (§ 556g(3) BGB). For that reason, document the basis of your calculation cleanly from the outset.

What happens if the rent is too high?

If the tenant considers the rent excessive, they can formally object (qualifizierte Rüge, § 556g(2) BGB). From the point a valid objection is received, they owe only the permissible amount and can reclaim the excess paid. An over-set rent is therefore not a one-off but an ongoing risk across the whole tenancy.

Common mistakes

• Vergleichsmiete determined wrongly or not at all. Calculating without checking the Mietspiegel makes it easy to breach the 10% limit unnoticed.
• Assuming an exception but giving no disclosure. Without the pre-contractual disclosure in text form, the exception does not apply — even if its conditions are met.
• Citing the wrong Vormiete. A Vormiete that was itself impermissibly inflated offers no protection; what counts is the last owed, permissible rent.
• Confusing the Neubau cut-off. What matters is first use and letting after 1 Oct 2014, not the year of construction alone.
• Disclosing only in the contract. The information must exist before the tenant's contractual declaration, not just in the signed contract.

With HausMaus it's simpler

HausMaus checks a planned rent against the Mietpreisbremse before you re-let. Using the Mietspiegel logic in its rent-increase tooling, the app determines the ortsübliche Vergleichsmiete for the unit and compares your intended rent against it. If the asking rent would exceed the legal cap, HausMaus flags it before you let the unit — so you set a compliant rent from the start. For landlords, HausMaus costs 1% of the rent collected.