Pimping occurs according to Art. 195 StGB when someone introduces a person into prostitution, monitors their freedom of action or determines the conditions of their sex work in order to derive financial benefits from it.
The penalty is a prison sentence of up to 10 years or a fine. The renting of rooms at market prices, one-off agency fees or working as a salon operator with a business license is not considered pimping - as long as the sex workers are free to decide when, to whom and how they offer their services.