Hamburg Landlord Wants to Raise Your Rent? What the Kappungsgrenze and the Mietenspiegel Actually Allow

The Official Rule

A letter proposing a higher rent on the apartment you already live in can feel like something you simply have to accept, especially in a market as tight as Hamburg’s. German tenancy law actually gives you more room to check the numbers than most tenants realize, and Hamburg layers its own reduced cap on top of the federal rules besides.

Under Section 558 BGB, your landlord can only request your consent to raise the rent on an existing tenancy up to the local comparative rent, the ortsübliche Vergleichsmiete, and only once your current rent has already stayed unchanged for at least 15 months at the point the increase is meant to take effect. The demand itself can be sent earliest 12 months after your last rent increase took effect, and under Section 558a BGB it has to carry a real justification in text form, not just a figure: at least three comparable apartments, a reasoned appraisal from a certified expert, or the Hamburger Mietenspiegel itself.

Hamburg’s reduced Kappungsgrenze is set by the city’s own Kappungsgrenzenverordnung, issued under Section 558 Absatz 3 BGB. Because Hamburg has been designated an area where adequate housing at reasonable terms is particularly endangered continuously since September 2013, the cap has sat at a reduced 15 percent over any rolling three-year period ever since, instead of the national default of 20 percent. The current version of the ordinance, enacted 8 August 2023, took effect 1 September 2023 and runs through 31 August 2028, picking up directly where the previous five-year ordinance left off.

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The comparative rent your landlord has to work from comes from the same Hamburger Mietenspiegel 2025 used to check new-lease rents under the Mietpreisbremse, published 9 December 2025 with an April 1, 2025 reference date. Drawing on roughly 47,450 surveyed households, the Behörde für Stadtentwicklung und Wohnen calculated the citywide figure as a median for the first time, putting it at 9.94 EUR per square meter net cold rent, up just 1.12 percent from 9.83 EUR in the 2023 edition. Because the Hamburger Mietenspiegel is a qualified rent index (qualifizierter Mietspiegel), courts treat it as the most reliable source for your specific comparative rent, sorted by your apartment’s size and construction year and adjusted for its Wohnlage and features into a specific Mietspiegelfeld, a grid field rather than a single numbered row. Even if your landlord’s letter is instead built around three comparable apartments or a paid appraisal, the law still requires them to name your Mietspiegelfeld whenever the Mietenspiegel actually covers your apartment.

Your response has a real, fixed deadline. Under Section 558b BGB, you have until the end of the second calendar month after you received the letter to answer, in text form, whether that is full consent, partial consent to just the portion that actually clears both the Mietenspiegel and the Kappungsgrenze, or a reasoned refusal. Staying silent is not itself consent, but paying the higher amount for three consecutive months without objecting can be read as implied consent through your conduct, so answering in writing is worth doing rather than letting the new amount go through on autopilot. If you withhold consent and your landlord wants to pursue it, they then have exactly three further months to file a Zustimmungsklage, a lawsuit asking a court to order your consent, and if that deadline passes too, the whole increase request lapses and they would have to start over with a fresh letter.

You also get an option the letter itself will not mention. Under Section 561 BGB, receiving a Section 558 increase demand gives you a special right to terminate the tenancy early: by the end of the second month after the letter arrived, effective at the end of the following month, roughly three months’ notice regardless of your ordinary notice period. If you actually give this notice, the rent increase never takes effect at all for the time you have left in the apartment. It is a genuinely useful option if the increase would push the apartment out of your budget and you would rather move than negotiate.

You do not have to work out whether the numbers add up on your own. Mieterverein zu Hamburg runs a free online check that walks you through your address and apartment details and compares your net cold rent per square meter against the Mietenspiegel, with no membership required. If the result looks concerning or you want a second opinion before responding, the association’s tenant hotline (040 87979-345, Beim Strohhause 20, 20097 Hamburg) can review the specific Mietspiegelfeld your landlord used and confirm whether the Kappungsgrenze math actually holds up.

What Real People Say

Hamburg tenant advisors describe the most common mix-up as conflating two entirely different mechanisms: the Mietpreisbremse’s 10 percent buffer over the Mietenspiegel, which only applies the day you sign a brand-new lease, and the Kappungsgrenze, which applies to an existing tenancy and works off a completely different baseline, what you were paying three years ago, not what the Mietenspiegel says today. Renters who assume the new-lease rule applies to their own increase letter often either object to the wrong thing or miss a legitimate objection entirely.

The Section 561 special termination right shows up less often in casual conversation, mostly because the increase letter never mentions it and most tenants only learn about it from a tenant association or a lawyer after the fact. Advisors who do flag it early describe it as a genuine relief for tenants who were quietly assuming their only choices were pay up or fight, when moving out on a shortened notice period was available to them the whole time.

Mieterverein zu Hamburg’s own reviewers report that outright fabricated numbers are rare; what turns up far more often is a Mietspiegelfeld that does not actually match the apartment, usually because the construction year or a feature that should have shifted the classification got applied incorrectly, quietly pushing the whole calculation upward.

Step by Step

1. Check the timing first. Has your rent actually been unchanged for 15 months, and did your last increase take effect at least 12 months before this letter arrived?
2. Identify the justification and find your own Mietspiegelfeld, using Mieterverein zu Hamburg’s free online check or the official Mietenspiegel query tool, based on your apartment’s size, construction year, Wohnlage, and features.
3. Compare the requested rent against both ceilings: your Mietspiegelfeld value, and 15 percent above what you paid three years before the increase takes effect. Whichever is lower is what actually applies.
4. If anything looks off, get a second opinion from Mieterverein zu Hamburg’s tenant hotline before you respond.
5. Respond in writing before the end of the second calendar month after receipt: full consent, partial consent to the correct portion, a reasoned refusal, or your Section 561 special termination notice if you would rather move.

Compliance Note

This page explains the general rules around Mieterhöhung requests, the Kappungsgrenze, and the Mietenspiegel 2025 in Hamburg, but this is not legal advice, and the correct comparative rent and Mietspiegelfeld for your specific apartment can only be confirmed through the official Mietenspiegel query tool or Mieterverein zu Hamburg.