TRAP:Yearly utility bills (Nebenkostenabrechnung) frequently include charges that landlords cannot legally pass to tenants, such as building repairs or management fees. A single formal letter from a Mieterverein lawyer often recovers hundreds of euros in unfair charges.

TRAP:Landlords and agents often demand the entire 3-month deposit before handing over keys. Lease clauses requiring the full deposit upfront are legally invalid (§ 551 BGB). Landlords must also keep your money in an insolvency-protected escrow account separate from their personal funds.

TRAP:If everyone signs the lease together as joint main tenants (Hauptmieter), German law considers you all jointly liable (§ 421 BGB). If a flatmate moves out or stops paying rent, the landlord can legally demand the entire rent and repair costs from you. You also cannot leave the lease on your own unless all other tenants and the landlord agree in writing.