The previous tenant wants key money from me. Should I pay?

Key money is money the previous tenant or a middleman asks for in return for 'leaving the flat to you'. There is no such legal payment in Germany. If you sign the rental contract with the landlord, there is no legal reason to pay the previous tenant anything.

Sometimes it is framed as 'I spent money on the kitchen and bathroom, so pay me for that'. If the price is very high, this is also a kind of key money. When subletting (Untermiete), asking for more than the actual rent is also prohibited.

Key money is also used for scams. Sometimes the person asking for money is not even the real tenant: they get you to sign fake documents, take the money and disappear. If the person will not give you anything in writing, that is a serious warning sign.

Estate agents (Makler) do not take key money, only their legal commission (Provision). If someone says they are an agent, ask for their documents and tax number.

Contact the landlord directly, especially if it is a company, and explain what is happening. Do not sign or negotiate alone: take someone you trust with you. If you can, do not take a flat where key money is demanded at all.

For legal short-term flats you can use Wunderflats or HousingAnywhere, even if they cost a bit more. Meanwhile, keep looking for a long-term flat on ImmoScout24 (with a premium membership if needed) and through German estate agencies.