Check Index Rent on Renewal – Tenants in Germany

When renewing a lease with index rent, tenants in Germany should carefully check how the adjustment is regulated in the contract and whether the calculation is fair. Many rental agreements include index clauses that link the rent to the consumer price index; this affects long-term rent costs and monthly household planning. Tenants should understand which deadlines, calculation formulas and proofs the landlord may use and which legal limits apply. This text explains step by step what to check when reviewing index rent, which documents are useful, how to formulate objections and which courts or authorities are competent. The aim is to make practical decisions understandable and manageable for tenants in Germany.

What is index rent?

Index rent is a contractual agreement in which the rent is adjusted regularly to an index, usually the consumer price index. Such clauses must be clearly formulated in the rental agreement; if concrete calculation rules are missing, this can lead to uncertainties. Legal bases can be found in the German Civil Code (BGB) regarding general rental obligations and freedom of contract^[1].

What tenants should check before renewal

• Check the exact wording of the index clause in the contract and whether the calculation formula is specified clearly.
• Understand which index base (e.g. consumer price index) and which calculation period are used, and calculate an example.
• Check the landlord's notification deadlines and deadlines for objections (deadline) so you do not lose rights.
• Create a file with all letters, calculations, statements and receipts to secure evidence (evidence).
• Seek advice early from tenant advice or the local court if there are uncertainties (help).

Typical calculation and examples

Index rent is usually calculated as: base rent × (current index / base index). Example: base rent €600, base index 100, current index 105 → new rent = €600 × (105/100) = €630. Check whether the contract states rounding rules or caps. If the calculation is outside the contractual agreement, you can demand a correction or have it legally reviewed.

FAQ

What does index rent mean?

Index rent means that the rent is linked to the development of an index (usually the consumer price index); the adjustment is made according to the contractually agreed formula.

Can the landlord unilaterally change the index rent on renewal?

Only if an index clause is present in the contract and clearly formulated; otherwise changes require the agreement of both parties.

Who should I contact if the calculation is unclear?

Contact your local tenant advice service or the competent local court; procedural rules for legal action are governed by the Code of Civil Procedure (ZPO).^[2]

How-To

1. Read the lease carefully and mark the index clause.
2. Calculate a sample adjustment using the numbers stated in the contract.
3. Request a written breakdown of the calculation and the index values used from the landlord.
4. Observe deadlines for objections and document the date and method of sending your objections.
5. Use template wordings for objections or a termination letter if necessary and submit them with proof of delivery.
6. If no agreement is reached, consider court action at the local court and gather all evidence for the proceedings.

Help and Support

• Gesetze im Internet – BGB
• Bundesgerichtshof (BGH) – Decisions
• Federal Ministry of Justice – Information and Forms

1. [1] BGB §§ 535–580a – Gesetze im Internet
2. [2] Zivilprozessordnung (ZPO) – Gesetze im Internet
3. [3] Bundesgerichtshof – Decisions and Information