Guides / Rent & rent increases
Rent & rent increases
What rent is permitted, when it may rise and how to check an increase.
Whether a rent increase holds up comes down to a few levers: the ortsübliche Vergleichsmiete (local reference rent), the Kappungsgrenze cap of 15 or 20% in three years (§ 558 BGB), and the form of the notice. For landlords that means justifying it correctly, keeping the deadlines and obtaining consent. For tenants: check before you agree, many increases fail on their reasoning or exceed the cap.
Stepped and index-linked rent (§§ 557a, 557b BGB) and increases after modernisation (§ 559 BGB) follow their own rules. These guides walk through every variant, from the landlord's and the tenant's side, each with the governing statutes.
Guides for tenants
- How to read and use the Mietspiegel as a tenant (2026)
Reading the Mietspiegel: place your flat by age, size, location and fittings, read off the comparable rent per m² (§ 558c BGB), then check your rent.
- Is your Indexmiete increase correct? How to check (2026)
Check your Indexmiete increase yourself: the CPI formula, the minimum one-year gap, text form with index figures (§ 557b BGB) and what to do if it is wrong.
- Checking a Mieterhöhung: is the rent increase legal? (2026)
Check a Mieterhöhung: the rent must have been unchanged for 15 months and can rise by at most 20% in three years (§ 558 BGB). How to check it and respond.
- Mietpreisbremse check: are you paying too much rent? (2026)
Mietpreisbremse check: in designated areas the rent can be at most 10% above the local comparable rent. How to object and claim back what you overpaid.
- Modernisierung: tenant rights & rent increase (2026)
Modernisierung: the landlord can add 8% of the costs (§ 559 BGB), capped at €3/m². When you must allow the work, how to object and how to leave early.
- Checking a Staffelmiete or Indexmiete (2026)
Check a Staffelmiete or Indexmiete: fixed amounts and 12 months per step (§ 557a BGB), CPI link and text form (§ 557b BGB). Is the increase legal?
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