Rent Increase: When It Is Permissible and When You Don't Have to Agree
A rent increase is only effective under certain conditions and limits. Often you have to expressly consent to it – and you can refuse if the requirements are not met.
Increase up to the local comparative rent (§ 558 BGB)
The most common case: the landlord demands an adjustment to the local comparative rent. For this, the rent must have remained unchanged for at least 15 months, and the increase request must be substantiated – for example with a rent index, an expert appraisal, or three comparable flats.
The capping limit
Within three years the rent may rise by no more than 20 %; in areas with a strained housing market the limit is only 15 %. This capping limit applies in addition to the local comparative rent – both limits must be observed.
You have to consent
An increase under § 558 BGB does not take effect automatically: you have to consent to it. You have until the end of the second month after the request is received to do so (period for consideration). If you do not consent, the landlord must sue for consent. If the request is formally flawed, it is invalid.
Modernisation and agreed increases
After a modernisation, the landlord may pass on part of the costs to the annual rent (§ 559 BGB) – here separate limits and notification obligations apply. With a validly agreed graduated rent or index rent (§ 557 BGB), by contrast, the increase follows directly from the contract.
How to check the rent increase
Check: Has the 15-month waiting period been observed? Is the request properly substantiated? Is the capping limit respected? Is the local comparative rent not exceeded? Even a formal error can render the increase invalid.
Relevant law
Frequently asked questions
For an adjustment to the comparative rent, at the earliest when the rent has remained unchanged for 15 months, and within three years by no more than 20 % (or 15 % in strained markets).
For an increase under § 558 BGB, yes – it only takes effect once you consent. You have a period for consideration until the end of the month after next. With graduated or index rent, by contrast, the increase follows from the contract.
The maximum amount by which the rent may rise within three years: 20 %, or 15 % in areas with a strained housing market.
Yes, if the requirements are not met or the request is formally flawed. The landlord must then sue for consent; you do not have to accept an invalid request.
The modernisation surcharge under § 559 BGB follows its own rules and limits; the capping limit of § 558 BGB concerns the adjustment to the local comparative rent.
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General legal information based on your contract — not individual legal advice.