Rent Increase in Germany 2025

A rent increase under §558 BGB is the landlord's request to raise the existing rent to the level of the local reference rent (ortsübliche Vergleichsmiete). The prerequisite is that the current rent is below the local reference rent. The landlord must justify the rent increase in writing — for example by referencing the Mietspiegel (rent index), an expert's report, or comparable apartments. The rent increase requires the tenant's consent; without this consent, the landlord cannot implement it unilaterally.

Important: The rent increase to the reference rent level (§558 BGB) applies exclusively to existing tenancies. It must be distinguished from the Mietpreisbremse (rent brake, §556d BGB), which applies to new lettings, as well as from stepped rent and index rent, which follow their own statutory rules. It should also be noted that the rent increase to the reference rent applies only to privately financed apartments — for publicly subsidised housing (Sozialwohnungen), special rent regulations of the respective state laws apply. In practice, the rent increase to the reference rent is one of the most frequent points of dispute between tenants and landlords, which is why a careful review of both formal and substantive requirements is advisable.

For a rent increase under §558 BGB to potentially be effective, several statutory requirements must be met:

• Cap limit (Kappungsgrenze, §558 para. 3 BGB): The rent may increase by a maximum of 20% within three years. In areas with a strained housing market, the state government may lower this limit to 15% (§558 para. 3 sentence 2 BGB). This cap applies regardless of how far the current rent is below the reference rent.
• Local reference rent (ortsübliche Vergleichsmiete): The target rent after the increase must not exceed the local reference rent. This is determined using the qualified Mietspiegel, an expert's report, or at least three comparable apartments.
• Waiting period (Sperrfrist, §558 para. 1 BGB): At least 15 months must elapse between two rent increases. The increase request may be submitted at the earliest one year after the last rent increase and takes effect at the earliest from the 15th month.
• Written form (Textform, §558a BGB): The increase request must be made in written form and contain a comprehensible justification — such as a reference to the Mietspiegel with classification of the apartment.
• Consideration period: The tenant has a period for consideration until the end of the second month after receipt of the increase request. If the tenant does not consent, the landlord may file a consent action (Zustimmungsklage) at the local court within a further three months.

The law provides three different ways in which a landlord can justify a rent increase:

• Qualified Mietspiegel (§558d BGB): The most common and, in practice, most reliable method. A qualified Mietspiegel is compiled according to recognised scientific principles and approved by the municipality or interest groups. Where a qualified Mietspiegel exists, the landlord must reference it in the justification.
• Expert's report (Sachverständigengutachten, §558a para. 2 no. 3 BGB): The landlord may submit a report by a publicly appointed and sworn expert. This is more involved and costly but could be relevant for apartments with unusual characteristics.
• Comparable apartments (Vergleichswohnungen, §558a para. 2 no. 4 BGB): The landlord names at least three comparable apartments with their rent levels. The apartments must be comparable in terms of size, location, fittings, and year of construction. This method is used less frequently, as comparability can be difficult to demonstrate.

Besides the rent increase to the reference rent level, there are two other common forms of rent adjustment that are agreed at the time of signing the tenancy agreement: Index rent (§557b BGB) links the rent to the consumer price index published by the Federal Statistical Office. The adjustment occurs annually and only if the index has actually changed. Important: Where an index rent has been agreed, other rent increases under §558 BGB are excluded — with the exception of modernisation surcharges for energy-related refurbishment. Stepped rent (§557a BGB) provides for fixed increase stages determined by calendar date in the tenancy agreement. At least one year must elapse between individual stages.

Assessment: Index rents have led to considerable increases in times of high inflation, as the consumer price index reflects general price trends. With stepped rents, the development is transparent from the outset. Both forms generally exclude an additional rent increase to the reference rent level. It should also be noted that with an index rent, the adjustment does not occur automatically — the landlord must request the increase in writing, specifying the change in the index. With a stepped rent, by contrast, no separate declaration is required, as the increase stages are already set out in the tenancy agreement. In both cases, the tenant has a special right of termination if the rent adjustment could lead to a significant burden.

For construction measures that sustainably increase the value of the dwelling or sustainably save energy, the landlord may increase the annual rent by a portion of the costs incurred. This is known as the modernisation surcharge (Modernisierungsumlage) and follows its own rules, distinct from the rent increase to the reference rent level.

Cap limit for modernisation: The rent may increase by a maximum of 3 euros per square metre within six years of a modernisation. If the rent before modernisation was below 7 euros per square metre, the cap is only 2 euros per square metre. In addition, the modernisation must be announced in writing three months before it begins (§555c BGB).

If you have received a rent increase request, the following steps could be helpful:

1. 1Check the justification: Verify whether the landlord has correctly justified the rent increase — with a reference to the Mietspiegel, an expert's report, or comparable apartments. If a justification is missing, the request could potentially be invalid.
2. 2Check the cap limit and waiting period: Verify whether the 15-month waiting period has been observed and whether the cap limit (20% or 15% within three years) is exceeded.
3. 3Verify the reference rent: Use the official Mietspiegel or our calculator to estimate the local reference rent for your apartment. The target rent must not exceed this limit.
4. 4Use your consideration period: You have until the end of the second month after receipt of the request to consent or not. Use this period and seek advice if needed.
5. 5Consider partial consent: If the rent increase appears partly justified and partly excessive, you can consent to the justified portion and reject the rest.
6. 6Seek advice: In cases of uncertainty, we recommend your local tenants' association (Mieterverein) or a specialist tenancy law solicitor. RechtGuide does not provide legal advice under the RDG.

Frequently Asked Questions About Rent Increases

The 15 most important questions — answered clearly and concisely

Sources and Further Information

• §§ 557-559 BGB — Rent increase, index rent, stepped rent, modernisation surcharge (gesetze-im-internet.de)
• §558 BGB — Rent increase to the local reference rent (gesetze-im-internet.de)
• Federal Ministry of Justice — Information on tenancy law (bmj.de)
• Deutscher Mieterbund (German Tenants' Association) — mieterbund.de