(1) Where only one party to the purchase agreement on a flat or single family house has concluded a brokerage agreement, an agreement by which the other party is obliged to pay or reimburse the brokerage fee is effective only if the party that concluded the brokerage agreement remains under obligation to pay the brokerage fee in at least the same amount. The claim against the other party falls due only once the party that concluded the brokerage agreement has complied with its obligation to pay the brokerage fee or the broker provides proof thereof.
(2) Section 656c (1) sentences 3 and 4 applies accordingly.