Rent Increase 2026: Cap Limits, Rent Brake & How to Object
A Letter in Your Mailbox — and the Numbers Don't Add Up
You open your mailbox and there it is: a rent increase notice. €80 more starting next month. Just like that. Can they do this?
Sometimes yes, sometimes no. German rental law has clear rules about when and by how much your landlord can raise the rent — and what happens when those rules are ignored.
Three Types of Rent Increases
Not every increase works the same way. The law distinguishes three paths:
1. Adjustment to the Local Reference Rent (§ 558 BGB) The most common type. Your landlord can raise the rent up to the ortsübliche Vergleichsmiete — what comparable apartments in the same area cost. This must be backed by the local Mietspiegel (rent index), an expert opinion, or three comparable apartments.
2. Index-Linked Rent (§ 557b BGB) The rent is tied to the consumer price index. When inflation rises, so does your rent. Starting in 2026, the government plans to cap index-linked rent increases — the previously unrestricted link to inflation is being limited.
3. Graduated Rent (§ 557a BGB) Fixed increases at fixed dates, written into the lease from the start. There's little room to negotiate — what's agreed upon applies.
The Cap: Maximum 20% in Three Years
Even if your rent is below the local reference, your landlord can't increase it without limits. Section 558(3) BGB sets the Kappungsgrenze (cap limit): rent may rise by no more than 20% within three years. In areas with tight housing markets — which includes most major cities by now — the cap is only 15%.
Example: You pay €600 cold rent. The local reference rent is €800. Your landlord can still only raise it to €690 (15% of €600 = €90), not to €800.
Mietpreisbremse: Protection for New Tenancies
Since 2015, the Mietpreisbremse (rent brake) applies in tight housing markets (§ 556d BGB). For new leases, the rent may not exceed 10% above the local reference rent. The rent brake has been extended through the end of 2029.
Exceptions: New-build apartments (first occupied after October 1, 2014) and comprehensively modernized units are exempt. The brake also doesn't apply if the previous tenant was already paying more — the landlord may maintain that level.
When a Rent Increase Is Invalid
A rent increase must meet specific formal requirements. If even one is missing, the entire increase is invalid:
- No justification: The landlord must state what the increase is based on — Mietspiegel, expert opinion, or comparable apartments (§ 558a BGB)
- Waiting period not met: At least one year must pass after moving in or the last increase (§ 558(1) BGB)
- Cap exceeded: More than 20% (or 15%) in three years is not allowed
- Oral only: The increase must be in written form — a verbal announcement in the stairwell doesn't count
- Wrong Mietspiegel: The landlord uses an outdated or inapplicable rent index
How to Respond
After receiving the increase notice, you have until the end of the second month following receipt to respond (§ 558b(2) BGB). If you receive it on March 15, your deadline is May 31.
During this time:
- Check the Mietspiegel — Does the stated reference rent match? You can find your city's qualified Mietspiegel online or through the tenant association.
- Check the formalities — Is there a proper justification? Was the waiting period observed? Is the cap respected?
- Consider partial consent — If the increase is partially justified, you can agree to the valid part and reject the rest.
If you don't agree and the landlord sues for consent, a court decides. Important: Until there's a legally binding judgment, you continue paying the old rent. You don't have to pay more just because your landlord pressures you.
Modernization Surcharge — The Other Lever
After modernizations (not mere repairs), landlords can pass on up to 8% of costs annually to the rent (§ 559 BGB). The increase may not exceed €3 per square meter within six years — or €2 if the starting rent was below €7/sqm (§ 559(3a) BGB).
A new roof counts as maintenance — no surcharge allowed. New thermal insulation or an elevator installation counts as modernization — surcharge generally permitted. The distinction is often disputed in practice.
Common Landlord Mistakes with Rent Increases
| Landlord's mistake | Consequence |
|---|---|
| No reference to Mietspiegel | Increase formally invalid |
| Waiting period ignored | Increase invalid |
| Cap exceeded | Only valid up to the cap |
| Modernization costs not itemized | Surcharge invalid |
When to Get Help
For straightforward Mietspiegel-based increases, checking the rent index yourself is often enough. But when your landlord argues with expert opinions, claims a modernization surcharge, or threatens termination — it's worth consulting a tenant association (~€60–90/year) or a specialist attorney.
And for a quick initial assessment: ask MieterHelfer.
Why MieterHelfer Helps with Rent Increases
Describe your situation — for example, "landlord wants 15% more, Mietspiegel says otherwise" — and get an assessment within seconds. MieterHelfer knows the current legal situation, checks the key points, and shows you your options.
Free, no registration, available around the clock. Not a substitute for a lawyer — but the right first step.