All question that clarify whether the future tenant will be able to pay for his or her future flat - for example questions about income, workplace, etc. - must be answered honestly. You also have to be honest about statements - written or oral - about the amount of people that will be living in the flat.

Everything that is not directly connected with the contract is none of the landlord's business. This covers for example questions whether children are planned, whether your wife is pregnant or if your partner is a foreigner, how your ideal flat looks like or if you are member of a political party. In such cases you can say whatever you like or what you believe the landlord would like to hear.

To make sure that the future tenant can actually pay for the flat, many landlords require a so called "Schufa Selbstauskunft". This is a declaration about your financial department record record issued by a clearing house - the Schufa, located in Berlin. If you want the flat, you have no choice but to get this piece of paper. Some real estate agents may ask you to pay for paperwork. If they do just that, demand your money back - after you signed the contract.