Buying a Tenanted Flat: §566 BGB in Practice

Kauf bricht nicht Miete ("sale does not break lease") is §566 BGB. If you buy a flat that was already let and handed over to the tenant, you step into the existing contract exactly as it stands. You cannot renegotiate the rent, the fixtures, or that verbal permission to keep a dog. Side agreements, Staffelmiete (pre-agreed rent steps), Indexmiete (inflation-linked rent) and past consents all come with it.

The timing trap. You become landlord only on Eigentumsumschreibung (registration as owner in the Grundbuch), not at the notary and not at the agreed Besitzübergang / Nutzen-Lasten-Wechsel (the economic handover date). In the gap – often 2–6 months – the seller is still the legal landlord. A good Kaufvertrag assigns the rent claims to you from the handover date and gives you a power of attorney to act. Only after registration should you notify the tenant in Textform with your new bank details.

The deposit. §566a BGB: you inherit the Kaution obligations whether or not the seller ever gives you the money. If the tenant leaves in year four, you repay it. The seller stays secondarily liable – but that is a lawsuit, not a plan. Insist the deposit (plus accrued interest, held in a separate account under §551 BGB) is transferred at completion, with written confirmation of the amount.

Ask for, before signing: the original Mietvertrag plus every Nachtrag, the Übergabeprotokoll, deposit proof, the last two Betriebskostenabrechnungen, a rent payment history, and any Mieterhöhung or Modernisierungsankündigung already served.

One more: if the flat was converted into Wohnungseigentum after the tenant moved in, the tenant has a Vorkaufsrecht (right of first refusal, §577 BGB) on the first sale. Confirm the notary handles that notification – a botched one creates damages claims.