The Mietkaution: what §551 BGB actually says

§551 of the Bürgerliches Gesetzbuch is short and tenant-shaped. The cap: the security may not exceed three times one month's rent, excluding operating costs shown as a flat rate or advance (« höchstens das Dreifache der auf einen Monat entfallenden Miete ohne die… Betriebskosten »). The instalments: a tenant asked for a cash deposit is entitled to pay in three equal monthly parts, the first at the start of the tenancy, the next two with the following rents — the landlord cannot demand it all upfront. The custody: the landlord must place a cash deposit with a bank, separate from their own assets, at the standard savings rate, with the interest accruing to the tenant.

Agreements that deviate against the tenant are void under the section's final clause — the cap and the instalment right are not negotiable away in the lease's small print.

Source: Gesetze im Internet, § 551 BGB — Begrenzung und Anlage von Mietsicherheiten, read 4 September 2026.

The cap keys off the Kaltmiete — the cold rent, before the Nebenkosten advance that German listings quote alongside it. Three months of cold rent in a big-city market is a serious sum, which is why the instalment right exists and why the market has grown alternatives (deposit guarantees and insurance products) that trade the lump sum for a fee; those are commercial products outside the statute, worth reading as carefully as any policy.

Against the neighbours, Germany's ceiling is the outlier: France caps the standard unfurnished deposit at one month, and the Dutch Good Landlordship Act caps at two. Budgeting a German move means budgeting the Kaution alongside the first rent.

The Kaution is one line of the German arrival sequence — Anmeldung, the Steuer-ID that follows it, the bank account the deposit moves through, and the insurance obligations attached to your permit type, which the Germany hub documents from the sources. The checklist prints the sequence:

Print the moving checklist