(1) The commercial agent is entitled to a commission as soon as, and to the extent that, the trader has executed the transaction. A divergent agreement may be made, but the commercial agent will be entitled, upon execution of the transaction by the trader, to a reasonable advance which will be due not later than the last day of the following month. Irrespective of an agreement, however, the commercial agent is entitled to a commission as soon as, and to the extent that, the third party has executed the transaction.
(2) If it is established that the third party will not perform, there will be no right to a commission; any amounts already received are to be returned.
(3) The commercial agent also will be entitled to a commission if it is established that the trader fails to execute the transaction at all or executes the transaction only partially, or in a manner divergent from the initial agreement. No right to a commission will exist in the event of failure to execute if, and to the extent that, such failure is due to circumstances for which the trader is not responsible.
(4) The claim to a commission becomes payable on the last day of the month in which such claim is to be settled pursuant to section 87c (1).
(5) Any agreements deviating from subsection (2) first part of the sentence, or from subsections (3) and (4), to the detriment of the commercial agent, are ineffective.