ROUTE
Rent Increase: Check and Respond
Received a rent increase letter? Not every increase is valid. How to check the justification and cap, meet the consent deadline and recognise modernisation and index rent.
β Checked: 20/07/2026
A letter announcing a rent increase looks like a statement of fact, but in German law it is a request for your consent. The landlord cannot raise the rent unilaterally: they must name a ground, substantiate it and wait for your agreement β or have a court supply it.
COSTS AND DEADLINES
Deadlines you cannot miss
- Consent period (reflection period): to the end of the second month after receiptRent Increase: deadlines and responsehard deadline
Amounts follow official fees as of each stepβs verification date. Your city may charge a different rate β check the step itself.
βΊ More about this route
Three things need checking: whether the waiting period since the last increase has expired, whether the cap on increases over a three-year period has been respected, and whether the increase is substantiated by a permitted means β the local rent index, comparable flats or an expert report.
This three-step route covers every variant: the ordinary increase up to the local comparative rent, the period you have to respond and the consequences of agreeing or refusing, and the special cases β increases after modernisation and index or stepped rent contracts, where entirely different rules apply.
WHERE PEOPLE MOST OFTEN LOSE MONEY AND TIME
- Quietly starting to pay the new amount. Payment counts as consent to the increase, and challenging it afterwards is barely possible.
- Not checking the waiting period and the cap. Both limits apply regardless of the justification, and breaching them makes the demand ineffective.
- Ignoring the letter entirely. Silence gives no protection: once the period expires the landlord can sue for consent.
- Treating a modernisation increase as an ordinary one. It has its own calculation and its own ceiling, and the usual limits do not apply to it.
FREQUENTLY ASKED QUESTIONS ABOUT THIS ROUTE
Do I have to agree to a rent increase?βΎ
An ordinary increase up to the local comparative rent requires your consent. If the demand is justified and the deadlines were kept, a refusal usually leads to a claim in which the court substitutes that consent.
How long do I have to respond?βΎ
Until the end of the second calendar month after the letter arrives. During that period the rent may not be raised, and that time is exactly what the check on the justification is for.
How do I check whether the increase is justified?βΎ
By comparing it with your cityβs rent index for the size, location and construction year of the flat. The landlord must state the means of justification, and you can verify it yourself or through a tenantsβ association.
Do the limits apply to an index-linked rent?βΎ
No, with index or stepped rent contracts the rent changes by the mechanism agreed in advance, and the usual limits do not apply. What needs checking there is the contract itself and the accuracy of the calculation.