October 13, 2026
Index-linked rent in Germany (Indexmiete): rules and how to calculate it
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An index-linked rent (Indexmiete) is a rent agreed in a German lease that follows the consumer price index for Germany. When consumer prices rise, the landlord may raise the rent in the same proportion, no sooner than twelve months after the last change and only with a notice in text form. When prices fall, the tenant can ask for a reduction. If you are looking for a new flat in Berlin, you can find Waitly's Berlin waitlists here.
Last updated: 13 October 2026.
In short
Index-linked rent is governed by section 557b of the German Civil Code (BGB). It follows the consumer price index published by the Federal Statistical Office. The rent must stay unchanged for at least a year at a time, and an additional increase to the local comparative rent is not allowed. A new rent is due from the start of the second month after the notice arrives. From September 2025 to September 2026 the index rose by 3.26 percent. A legal cap is planned but not yet passed.
What is an Indexmiete?
With an Indexmiete, tenant and landlord agree in writing that the rent is linked to the price index for the cost of living of all private households, as calculated by the Federal Statistical Office. This is set out in section 557b BGB. The index meant here is the consumer price index (Verbraucherpreisindex, VPI).
The index applies to the net cold rent (Nettokaltmiete). Advance payments for service charges are adjusted separately. An index clause can be agreed when the lease is signed or later, but it always has to be in writing. Check this clause as carefully as the other key points before signing a Mietvertrag.
Index-linked rent is one of three ways rent can rise during a tenancy in Germany. The others are graduated rent (Staffelmiete) with fixed steps, and an increase up to the local comparative rent, which our article on rent increase limits in Germany explains.
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How is index-linked rent calculated?
The new rent equals the old rent multiplied by the new index value and divided by the old index value. What counts are the index points, not the published inflation rate. Both values must come from the same index series, currently with base year 2020 equal to 100.
Here is how to work it out step by step:
Find the index value for the month of the last rent change or the start of the lease.
Find the current index value in the Federal Statistical Office's table.
Divide the new value by the old one and subtract 1. That is the percentage change.
Multiply the current net cold rent by the ratio of the new value to the old value.
Worked example with real figures
According to the Destatis table, the consumer price index stood at 122.6 in September 2025 and at 126.6 points in September 2026. That is a rise of 4.0 points or 3.26 percent.
With a net cold rent of 900.00 euros, the landlord calculates: 900.00 euros times 126.6 divided by 122.6 equals 929.36 euros. The rent therefore goes up by 29.36 euros a month. If the notice arrives in October 2026, the new rent is due from December 2026.
With every increase, check that the landlord has compared the right months. The starting value is the index at the time of the last adjustment, not the value at the start of the lease if the rent has already been raised since then.
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What rules apply to an Indexmiete increase?
An index increase only takes effect if the landlord declares it in text form, for example by letter or email. The notice has to state the change in the index and either the new rent or the increase in euros. Your consent as the tenant is not needed.
Under section 557b BGB, these rules apply:
The rent must stay unchanged for at least a year at a time, apart from service charge adjustments and certain modernisations.
An increase to the local comparative rent under section 558 BGB is excluded while the index rent applies.
A modernisation surcharge is only possible in narrow exceptions, for example when the landlord is not responsible for the work being needed.
The new rent is payable from the start of the second month after the notice arrives. Nothing can be charged retroactively.
Agreements that put the tenant at a disadvantage are void.
The landlord does not have to raise the rent every year. If they skip a year, they can later claim the full index change since the last adjustment. Because the comparative rent plays no role, the rent index (Mietspiegel) rules usually do not help you with an Indexmiete.
Indexmiete and the rent brake in Berlin
With an index-linked rent, the rent brake (Mietpreisbremse) only applies to the starting rent. In Berlin, the rent for a new tenancy may be at most ten percent above the local comparative rent, and the Senate has extended this rule until the end of 2029.
Later increases in line with the index are not measured against the rent brake. Over the years, an index-linked rent can therefore climb above the local comparative rent in Berlin. Check at the start of the tenancy whether the starting rent was lawful. Our article on the Mietpreisbremse in Berlin explains what applies.
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The planned cap on index-linked rents
On 29 April 2026, the federal government approved a bill to limit index-linked rents in tight housing markets. If the index rises by more than 3.0 percent in a year, only half of the part above that threshold could be passed on to the rent.
In the worked example above, about 3.13 percent would count instead of 3.26 percent. The bill is before the Bundestag as printed paper 21/6807. As of 13 October 2026 it has not been passed, and the details and the start date may still change.
Pros and cons of index-linked rent
For tenants, index-linked rent has clear advantages:
Increases are transparent and tied to an official statistic.
Increases based on the Mietspiegel are excluded.
When inflation is low, the rent often rises more slowly than market rents.
If prices fall, you can ask for a reduction.
The downsides show up when inflation is high:
When energy and food prices rise sharply, your rent rises too, just as your other costs are already growing.
Over time, the rent can drift away from the local comparative rent.
The exact size of future increases cannot be planned.
With graduated rent, by contrast, the increases are fixed from the start. Our comparison of whether you should accept a Staffelmiete shows which option suits you better.
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Frequently Asked Questions
Can I refuse an Indexmiete?
Before signing, you can negotiate the clause or decide not to sign. Once the index rent has been validly agreed, later increases do not need your consent.
Where can I find the current consumer price index?
The Federal Statistical Office publishes the monthly values in its consumer price index tables, usually during the following month. Always use values with the same base year for both dates.
Does the Indexmiete apply to service charges?
No. The index only applies to the net cold rent. The landlord adjusts advance payments for service charges and heating separately after the annual statement.
Looking for a flat in Berlin
An index-linked rent is no reason to turn down a good flat, but you should run the numbers on the clause before signing. If you are searching in Berlin, you can sign up for landlords' waitlists and interest lists on Waitly and get updates by email. Signing up improves your chances, but it does not guarantee a flat.
