The Procuring Cause, also known as the "predominant efficient cause" or the "contributing cause," is the effort, which brings about the desired result.  When a home is on the market, the desired result is the successful sale of that property.

Under an open listing, the broker who is the procuring or effective cause of the sale is the one entitled to the commission.  A broker can be the procuring cause even though it is only indirectly through his or her efforts that the property is sold.  For example, if the broker sent a prospective buyer to the seller's home and the homeowner then sells the property to that buyer, the broker is considered the procuring cause of the sale and is entitled to the commission. 

With the exclusive-right-to-sell listing agreement, the broker is entitled to a commission if the property is sold by the seller or by anyone else, such as the buyer's broker or selling agent.  This method eliminates most procuring cause controversies.  Procuring cause issues sometimes arise, however, in disputes between the cooperating broker acting as a subagent and the listing broker, where both advise the buyer without knowledge of the other's involvement.  Issues also arise when more than one buyer's broker works with the buyer. 

Several state Realtor® boards have adopted guidelines by which procuring cause disputes may be settled.  Different rules may apply when the cooperating broker is a buyer's agent.  Procuring cause panels try to determine from all the facts who it was that initiated and carried forth the sequence of events that resulted in a successful transaction.