Index Rent and Rent Cap: Tenants in Germany

Many tenants in Germany are unsure how index rent and the rent cap interact. This article explains in clear language which rules apply to rent adjustments, which misconceptions are common and which steps you as a tenant should take to be secure. We show when an adjustment due to an index clause is legally possible, how the rent cap works and which deadlines and proofs are important. The aim is to enable you to correctly classify offers and letters from the landlord, use appropriate forms and — if necessary — contact the right authorities or courts. Concrete examples and references to official forms make practical implementation easier.

What do index rent and rent cap mean?

With an index rent, the amount of the rent is tied to the development of a price index (usually the consumer price index). Adjustments are made automatically by agreement in the tenancy contract, not as individual rent increases under § 558 BGB.^[1] The rent cap limits the permissible rent level for new rentals in areas with tense housing markets.

Common misconceptions

• The rent cap automatically applies to existing index rents.
• Landlords can freely set index adjustments without a contractual basis.
• All adjustments must be paid immediately without any possibility to object.
• Receipts and documentation are only important in a dispute.

How tenants should respond

If you receive an adjustment, first check the tenancy agreement and ask the landlord for a written calculation. Request evidence of the index basis and the applied index and note the date of the letter. Respond within set deadlines and use a written reply to secure your position.

• Request a detailed written calculation of the rent increase.
• Keep rent payments, transfer receipts and correspondence organized.
• Contact the local tenant advice or the district court for guidance if unclear.

Forms and templates (official)

Important official form guidance for tenants:

• Termination letter (template) from the Federal Ministry of Justice: use it only if you want to terminate yourself and include date, signature and exact apartment details.
• Complaint form for eviction or payment claims: in prolonged disputes usually to be filed at the competent local court.

Frequently asked questions

Does the rent cap apply to contract renewals?

For new rentals and partly for renegotiations, the rent cap can apply; for existing index rents the contractual agreement remains decisive.

Can I challenge an index clause retroactively?

A challenge is possible if the clause is invalidly worded or violates legal provisions; legal advice and court clarification at the local court are often necessary.^[2]

What deadlines must I observe when objecting?

Replies and objections should be made promptly; for court proceedings the deadlines of the Code of Civil Procedure for complaints and service apply.^[3]

How-to

1. First check your tenancy agreement for an index clause and its exact wording.
2. Request a detailed calculation and the basis of the index in writing.
3. Document all payments and communications with the landlord.
4. Use advice from the local consumer or tenant advice center.
5. Consider court action together with advice at the local court if disagreements persist.
6. Seek an amicable solution with the landlord where possible, documented in writing.

Help and support

• Bürgerliches Gesetzbuch (BGB) – §§ 535–580a
• Zivilprozessordnung (ZPO) – Procedures for eviction claims
• Federal Court of Justice (BGH) – case law on tenancy

1. [1] Gesetze im Internet – BGB
2. [2] Gesetze im Internet – ZPO
3. [3] Bundesgerichtshof – BGH