Checking a Staffelmiete or Indexmiete (2026)

What are a Staffelmiete and an Indexmiete?

A Staffelmiete (stepped rent) and an Indexmiete (index-linked rent) are two special forms of rent in which future increases are agreed in the lease itself. They do not follow the ordinary procedure for a Mieterhöhung (rent increase) up to the ortsübliche Vergleichsmiete (local comparable rent) under § 558 BGB – that route is covered in the guide Checking a Mieterhöhung.

The most important fact first: even an agreed Staffel- or Indexmiete is bound to fixed legal conditions. If one of them is wrong, the increase is invalid – and you do not have to pay it. With an Indexmiete there is an extra point: the increase is only owed once the landlord has properly declared it.

Is my Staffelmiete legal? (§ 557a BGB)

A Staffelmiete sets different, pre-defined rents for set periods. For it to be valid, four points must hold:

1. Fixed euro amounts. Each step must appear in the contract as a concrete sum – "from 1 January 2027: 920 €". A bare percentage is not enough (§ 557a Abs. 1 BGB).
2. At least 12 months per step. Between any two steps the rent must stay unchanged for at least one year (§ 557a Abs. 1 BGB).
3. Schriftform (written form). The agreement must be made in writing.
4. No extra increase. During the term, increases under §§ 558 to 559b BGB are excluded (§ 557a Abs. 2 BGB).

If one of these is wrong, the affected step is invalid – and the last validly agreed rent continues to apply.

Has my Indexmiete been increased correctly? (§ 557b BGB)

With an Indexmiete the rent is tied to the Verbraucherpreisindex (consumer price index, VPI) published by the Statistisches Bundesamt (Federal Statistical Office). When the index rises, the landlord may adjust the rent – but only if done correctly:

1. At most once a year. Between two adjustments the rent must stay unchanged for at least 12 months (§ 557b Abs. 2 BGB).
2. Declared in Textform. The landlord must actively declare the increase in Textform (text form) – letter, email or fax (§ 557b Abs. 3 BGB). It does not take effect automatically.
3. Old and new index plus the new rent. The notice must state the change in the price index – that is, the old and the new index value – and the new rent or the increase amount, so you can check it (§ 557b Abs. 3 BGB).
4. No extra increase. A Mieterhöhung up to the ortsübliche Vergleichsmiete under § 558 BGB is excluded during the term (§ 557b Abs. 2 BGB).

Achtung (caution): An Indexerhöhung (index increase) is only owed from the beginning of the month after next following receipt of a proper, calculable notice (§ 557b Abs. 3 BGB). Do not pay more before you have checked the notice – without the old and new index value stated, the increase is not due.

How do I recalculate an index increase?

What matters is the percentage change in the VPI, applied to the starting rent. The formula:

new rent = old rent × (current VPI ÷ base VPI)

The base VPI is the index level at the last setting (start of the lease or last increase); the current VPI is the level at the time of the increase.

A worked example:

Value	Example
Old Nettokaltmiete (net cold rent)	800.00 €
Base VPI (last setting)	112.0
Current VPI	118.5
Index change	+5.80 %
New rent (800 × 118.5 ÷ 112.0)	846.43 €

Always recalculate yourself. If the new index value the landlord quotes does not match the official VPI of the Statistisches Bundesamt, or the computed rent differs, you can object to the increase at that level.

Staffelmiete or Indexmiete – what do I check for each?

Check	Staffelmiete (§ 557a)	Indexmiete (§ 557b)
Form of the increase	fixed euro amounts in the lease	tied to VPI, declared in Textform
Minimum interval	12 months per step	12 months between adjustments
Automatic?	yes, on the agreed date	no – only after a notice
What must be stated?	amount and date of each step	old + new index and new rent
§ 558 on top?	no	no
Mietpreisbremse (§ 556d)?	yes – each step too	yes – on the starting rent

Does the Mietpreisbremse apply here too?

Yes. In areas with a Mietpreisbremse (rent cap), the starting rent of a Staffel- or Indexmiete at the start of the tenancy may exceed the ortsübliche Vergleichsmiete (local comparable rent) by at most 10 % (§ 556d BGB). With a Staffelmiete, each individual step is also measured against that limit (§ 557a Abs. 4 BGB). How to recalculate this and reclaim overpaid rent is in the guide Checking the Mietpreisbremse.

Common mistakes by tenants

• Accepting percentages in the step. A Staffelmiete needs fixed euro amounts; a pure percentage step is invalid (§ 557a Abs. 1 BGB).
• Paying the index increase straight away. It is only owed from the month after next following receipt of a proper notice (§ 557b Abs. 3 BGB).
• Not recalculating the index. Compare the quoted VPI with the official figure from the Statistisches Bundesamt.
• Forgetting the Mietpreisbremse. Even a contractually agreed rent may not exceed the 10 % limit at the start of the tenancy (§ 556d BGB).
• Accepting an extra § 558 increase, even though it is excluded alongside a Staffel- or Indexmiete.

HausMaus makes this easier

HausMaus is free for tenants. The app checks whether a Staffel or index step is correctly calculated and within the law, and helps you decide – with the rent-increase decision helper – whether to consent or object. On top of that, the Mietpreisbremse check (§ 556d BGB) confirms whether your starting rent stays within the legal limit, and the Vertragsanalyse (lease analysis) explains the Staffel or index clause in your contract.

See pricing – 1 % of collected rent, free for tenants →